eDAQ Wiki - User contributions [en]

Frequently Asked Questions Electrodes

2021-08-31T23:06:13Z

Oliver: /* Other Electrodes */

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
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= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]
* DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
* Remove the cap protecting the tip before use by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

Download the pdf Instruction Sheet from: [[File:ET069 ET072 Instruction Sheet.pdf]]

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== ET073 Use in Organic Solvents ===

'''Question:''' I want to use the eDAQ [https://www.edaq.com/ET073-1 ET073] Refillable Miniature Ag/AgCl Reference Electrode in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last inquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of Hydroflex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the [https://www.edaq.com/ET070 Hydroflex reference electrode] hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of Hydroflex in the daily lab routine certainly is the application as RHE. You simply dip Hydroflex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As Hydroflex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

ANSWER

Usually when the user exchanges the hydrogen source (cartridge) in time - that means before the hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of, for example, 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

CLEANING

Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.

STORAGE

Always clean the microelectrode before storing:
* Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
* Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999% for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

=== What is the minimum sample volume required ? ===

As long as the electrode tip is fully submerged in solution. This depends on the electrode cell. A small vial with conical shaped bottom is recommended.

https://www.edaq.com/ET080-12

The other possibility is to use the electrode upside down. Just a droplet of sample will do. However, the tricky issue is to position the reference and counter electrode in the same sample droplet.

Connecting the C4D to the Agilent 7100 CE

2020-03-09T03:50:17Z

Oliver: /* Equipment Required */

[[File:DSC06643.JPG|300px|thumb|right|eDAQ C4D connected to the Agilent 7100 CE instrument.]]
[[File:DSC06232.jpg|300px|thumb|right|The C4D headstage in the Agilent cartridge. The round, silver UV detector cell can also be seen.]]

''This application note describes how to connect the eDAQ C4D system to the Agilent 7100 CE instrument. See [https://www.edaq.com/wiki/Connecting_the_C4D_to_the_Agilent_1600_CE this] application note for the Agilent 1600 CE instrument.''

== Introduction ==
The eDAQ C4D can be connected to the Agilent 7100 CE instrument, providing contactless conductivity detection for the instrument.
Both the C4D headstage and UV detector can be connected to the capillary at the same time, enabling both types of detection to be performed with a single sample injection.

== Equipment Required ==
* C4D hardware unit, either:
** [http://www.edaq.com/ER815 ER815 C4D Detector] to record both C4D and UV signals in ChemStation software,
** [http://www.edaq.com/ER815 ER815R C4D Detector] to record only the C4D signal in [http://www.edaq.com/ES280 PowerChrom] or ChemStation software, or
** [https://www.edaq.com/ER825 ER825R Two Channel C4D Detector] to record both C4D and UV signals in PowerChrom or ChemStation software
* [http://www.edaq.com/ET120 ET120 C4D Headstage for Capillary Electrophoresis]
* Agilent 7100 CE instrument with ChemStation software
* Signal cable: EC001-4 [http://www.edaq.com/EC001-4 BNC to BNC Cables]
* Trigger cable: modified version of EC071 Trigger cable with DB9 male (Agilent Remote) to DB9 female (ER815 I2C), available on special order
* [https://www.edaq.com/EC020 EC020 Standard Test Solutions for C4D Applications]

== Choice of Software ==
The data from both C4D and UV-Visible detectors can be recorded and displayed in real time. You can use either the eDAQ PowerChrom software or Agilent ChemStation software. Use the [Http://www.edaq.com/ET120 ET120 C4D Headstage] and select either the:
* [http://www.edaq.com/ER815 ER815 C4D Detector] can be configured by the user to use either [http://www.edaq.com/ES280 PowerChrom] or third-party software like Agilent ChemStation. The analog output from the ER815 can be connected to the input of the Agilent CE, so the ChemStation software records data from both detectors. The ER815R model includes PowerChrom software to record the C4D signal.
* [https://www.edaq.com/ER825 ER825R Two Channel C4D Detector], can also be configured by the user to use either [http://www.edaq.com/ES280 PowerChrom] or third-party software like Agilent ChemStation. The ER825R model includes PowerChrom software and can record the signal from both C4D and UV detectors.
* [http://www.edaq.com/ER225 ER225 C4D Data System] can also be used. The analog output of the Agilent UV-Visible detector is connected to the analog input of the ER225. PowerChrom software records the data from both detectors. The ER225 has digital outputs.

== Installing the C4D Headstage in the Agilent Cartridge ==
It’s easy to mount the C4D headstage inside the Agilent CE cartridge. Simply thread the capillary through the channel in the side of the C4D headstage and fix in place.

Ensure that you position the C4D headstage near the end of the capillary that is grounded, away from the end of the capillary where the high voltage is applied. This is to ensure that the high voltage doesn’t arc from the background electrolyte inside the capillary, through the thin wall of the capillary, to the headstage and on to the C4D hardware, which could damage the equipment.

You should ensure that the C4D headstage and its flat grey cable are at least 1 cm away from the capillary as it loops inside the cartridge. This is to prevent the high voltage inside the capillary from shorting through the headstage and its cable, which are both electrically grounded.

You should also ensure that the C4D hardware unit is connected to an electrical socket which is grounded.

== Installing the ER8x5 Hardware Unit ==

If you are using the ER815 or ER825 units, you have a choice of recording the data in either PowerChrom software or Agilent ChemStation software.

=== Using PowerChrom Software ===

You must have [http://www.edaq.com/ES280 PowerChrom software] to do this.

You must also have the Application firmware installed on the C4D hardware unit. The user can switch the firmware themselves, between Serial and Application firmware, using the ER8x5 Converter and Updater Software (download from [https://www.edaq.com/ES790 here] and find instructions in the [https://www.edaq.com/wiki/C4D_Configurator_Software video] and [https://www.edaq.com/edaq-product-manuals manuals]).

Set up the hardware and PowerChrom software as detailed in the [https://www.edaq.com/edaq-product-manuals manuals]. Connect the headstage to the capillary. You should connect the modified EC071 Trigger cable, from the CE instrument to the I2C connector at the back of the ER8x5 unit, so that the Agilent ChemStation software sends a message to PowerChrom software to trigger start recording.

'''Selecting C4D Settings''' The C4D settings (amplitude, frequency and headstage gain) should be selected in the PowerChrom software. Do not use the C4D Configurator Software when the ER815 and ER825 are configured with applications firmware, or when using the ER225.

[[File:CE-part configuration.jpg|300px|thumb|right|CE-part configuration.]]

=== Using Agilent ChemStation Software ===

You must have the Serial firmware installed on the C4D hardware unit. The user can switch the firmware themselves, between Serial and Application firmware, using the ER8x5 Converter and Updater Software (download from [https://www.edaq.com/ES790 here] and find instructions in the [https://www.edaq.com/wiki/C4D_Configurator_Software video] and [https://www.edaq.com/edaq-product-manuals manuals]).

You should refer to the Agilent 7100 Capillary Electrophoresis System User Manual, which can be downloaded from [https://www.agilent.com here]. The Agilent 7100 Capillary Electrophoresis System has a 20-bit AD converter built in. It enables voltage conversions ranging from 0 V to 1 V.

'''Signal Cable''' You should connect the analog output from the C4D hardware (“Delta K” BNC connector at the back of the ER8x5 unit) to the analog input of the Agilent 7100 CE instrument, using a BNC to BNC cable.

'''Setting Up ChemStation software''' Refer to the ChemStation manual. You must tell the software to accept a signal from an external detector. This is done from the dialog window shown in the "CE-part configuration" figure, which is accessible in the software under Instrument/configuration, CE-part configuration. In the "Analog In Signal" tick the "Acquire" box. Give it a name, like "C4D". Change “Signal unit” to V. Set the Multiplier to 1000 (this should mean that the software can record up to 1 V). Then in the eDAQ C4D Configurator software, set the Full Scale Output to 1V. This should mean that both the Agilent analog input and the eDAQ analog output are both set to 1 V.

'''Selecting C4D Settings''' The C4D Configurator software allows the setting up of the C4D settings (amplitude, frequency and headstage gain) of ER815 and ER825 C4D Detector when they are configured with the serial firmware. It provides a simple alternative to the use of direct serial commands. Download the C4D Configurator software from the [http://www.edaq.com/software-downloads Software Downloads]. The procedure for using this software is shown in a [https://www.edaq.com/wiki/C4D_Configurator_Software video] and has been written up as a pdf [https://www.edaq.com/edaq-product-manuals manual].

'''Procedure for connecting the ER8x5 to the Agilent 7100 and using Agilent ChemStation to record the data'''
# Install C4D Configurator software and C4D Profiler software to computer
# Connect ER815 C4D Detector to power and use USB to computer
# Connect headstage to C4D unit; make sure the power on the C4D unit is off!
# Use BNC to BNC cable. Connect it to the delta K connector at the back of the ER815. Connect the other end to the analog input on the right side (towards the back) of the Agilent 7100 instrument.
# Turn on C4D unit; On the computer, the operating system should install the driver
# Open C4D Configurator software
# Select 1000 kHz and click apply to all
# Select amplitude 80% and click apply
# Click green arrow and see the signal move in the window
# Push a piece of capillary into the headstage. Manually inject water or background electrolyte into the capillary to confirm you can see a change in signal in the C4D Configurator software.
# Turn on Agilent 7100 instrument and its software
# In ChemStation software, in the menu Instrument, Instrument Configuration, under Select Modules, double click CE (product number) to open the CE Part Configuration Instrument 1,
# Under analog input Signal, Click the Aquire check box, Signal name = C4D, signal unit = V, multiplier = 1000
# You may need to restart ChemStation software
# In menu View, click Online Signals, Signal Window 1 to open Online Plot window, click Change, on the left find the CE1A, G7100 Analog in (V) signal and click add so it moves to the right side "Selected Signals", click ok, you should see the C4D signal in the window
# Manually inject water or background electrolyte into the capillary to confirm you can see a change in signal in Agilent ChemStation software
# Put headstage on capillary
# Put cartridge in instrument
# When you have confirmed that ChemStation software is recording the C4D signal, you are ready to inject background electrolyte into the capillary, use the C4D Profiler software to work out optimum C4D settings (amplitude, frequency and headstage gain), and then use the C4D Configurator software to select those C4D settings

== Citations ==
* The eDAQ C4D was used with the Agilent CE for the analysis inorganic ions in drinking water. [http://dx.doi.org/10.1080/10826076.2013.825862 DOI: 10.1080/10826076.2013.825862]
** The C4D detected both anions and cations in a single injection. This was done by injecting the sample at both ends of the capillary and placing the C4D headstage at an appropriate position along the capillary.
** It was noted that C4D detection is an alternative and more flexible method of detection compared to the standard optical detection. The effective separation length can easily be adjusted by simply sliding the C4D headstage along the capillary, significantly facilitating the method development and the obtained separation efficiency.
** The estimated limits of detection (0.07 – 2 ppm) and defined limits of quantification (0.3 – 7 ppm) were comparable or better than those described for indirect UV detection, allowing much broader linear ranges (up to 120 ppm) for most of the studied ions.
* The Agilent CE was coupled with the eDAQ C4D for the simultaneous determination of atenolol and amiloride in pharmaceutical preparations. Good analytical performance with regards to linearity, reproducibility, and accuracy was achieved using the CE-C4D method. [http://dx.doi.org/10.1002/bmc.1390 DOI: 10.1002/bmc.1390]
* The determination of cis/trans isomers ofoctadec-9-enoic acid and other long chain fatty acids was performed using the Agilent CE with eDAQ C4D. The method was applied to the determination of fatty acids in margarine samples. The proposed method offers distinct advantages over the GC and HPLC methods, especially in terms of simplicity (without derivatization) and sensitivity. [http://dx.doi.org/10.1016/j.chroma.2013.03.014 DOI: 10.1016/j.chroma.2013.03.014]

How to Choose a Potentiostat

2020-02-12T04:14:15Z

Oliver: /* eDAQ Potentiostat Systems */

A potentiostat is a device that controls the potential between a pair of electrodes whilst measuring the resulting current flow.

== Operating Requirements ==

When choosing a potentiostat you need to have some idea of the voltage and current limits within which you wish to operate.

Most potentiostats offer applied potentials (voltages) of up to ±10 V. Sensitive potentiostats designed for accurate measuring of small currents (nanoamperes or less) typically offer maximum currents of up to 10 mA. Large current potentiostats (1 A or more) often do not provide small current ranges (less than microamperes), or else they are very expensive, or require 'headstage' current amplifiers. Analytical chemists usually require a mid-range potentiostat (nanoamperes to 100 mA or so). Electrosynthesis experiments usually require currents in excess of 10 mA, and a maximum current of 1 A, or more, is often useful if you need to generate a few grams of material in a reasonable timeframe.

== Number of Electrodes ==

=== Two-Electrode Potentiostats ===

A two-electrode potentiostat uses a working and counter electrode. A disadvantage of this arrangement is that if the electrodes are further apart than the resistance between them increases and the current decreases. Thus reproducible results can be hard to achieve if electrode surface area, or separation distance, varies. Polarographic oxygen, peroxide, and nitric oxide electrode meters are all examples of two-electrode potentiostats. Note that in each of these cases the electrodes (anode and cathode) are usually built into a single probe body so that the orientation and distance between the electrodes is held constant from one experiment to the next.

eDAQ two-electrode potentiostats are:

: [http://www.edaq.com/EPU352 EPU352 USB Biosensor isoPod]
: [http://www.edaq.com/EPU354 EPU354 USB dO2 isoPod]
: [http://www.edaq.com/EPU355 EPU355 USB Nitric Oxide isoPod]

: [http://www.edaq.com/EP352 EP352 Biosensor isoPod] for use with e-corder systems
: [http://www.edaq.com/EP354 EP354 USB dO2 isoPod] for use with e-corder systems
: [http://www.edaq.com/EP355 EP355 USB Nitric Oxide isoPod] for use with e-corder systems

Three- and four-electrode potentiostats can often be used as two-electrode potentiostats by connecting the voltage sensing (reference electrode) inputs to the appropriate current passing (auxiliary or working electrode) inputs, see below.

=== Three-Electrode Potentiostats ===

This is typically what people mean when they say a 'potentiostat'. With a 'three-electrode' potentiostat the potential is monitored between reference and working electrodes that are in close proximity, while the potential of a relatively distant auxiliary electrode is adjusted. The current flow is measured between the working and auxiliary electrodes. This has the advantage that no current actually passes through the reference electrode, so there is no electrolytic reaction occurring there, and thus the reference electrode potential can remain constant throughout the experiment. A consequence of this arrangement is that the potential between the working and auxiliary electrodes (the 'compliance' potential, which is usually not reported) can be many times the applied potential (depending on electrolyte resistance and distance between the electrodes). By attaching the potentiostat reference and auxiliary inputs to the same 'counter' electrode, a three-electrode potentiostat can be used as a two-electrode potentiostat. The following eDAQ Potentiostats below can be operated as three-electrode potentiostats.

: [http://www.edaq.com/ER466 ER466 Integrated Potentiostat]
: [http://www.edaq.com/ER467 ER467 High Current Potentiostat]
: [http://www.edaq.com/EA163 EA163 Potentiostat]
: [http://www.edaq.com/ER466 EA164 QuadStat]
: [http://www.edaq.com/EA362 EA362 Dual Picostat]

=== Bipotentiostats and Multiple Working Electrodes ===

A bipotentiostat system features a reference and auxiliary electrode, and two working electrodes, whose potentials can be independently adjusted while the current flowing through them is monitored. This principle can be extended to any number of working electrodes, for example the
: [http://www.edaq.com/EA164 EA164 QuadStat] controls up to four working electrodes, while the
: [http://www.edaq.com/EA362 EA362 Dual Picostat] is a bipotentiostat (ie can control up to two working electrodes).

Typically the potential between the reference and first working electrode is controlled and the potentials of subsequent working electrodes are offset relative to the first electrode to achieve the desired effect. These potentiostats are often used in 'electrochemical nose' systems.

=== Four-Electrode Potentiostats ===

The term 'four-electrode potentiostat' is usually reserved for a device with two reference ('voltage sensing') electrodes and two working ('current passing') electrodes. The potential difference between the two reference electrodes is controlled while the current flow between the two working electrodes is monitored. These potentiostats are commonly used to measure the current flow across a membrane separating two compartments, or across the interface of two immiscible solvents (an [http://en.wikipedia.org/wiki/ITIES ITIES] experiment). The
: [http://www.edaq.com/ER467 ER467 High Current Potentiostat] is a 4-electrode system with one working, one counter, and two reference electrodes for the measurement of currents across membranes (4-electrode voltage clamp), or the interface between two immiscible electrolyte solutions (ITES).
: [http://www.edaq.com/EA362 EA362 Dual Picostat] can be used in four-electrode mode
: [http://www.edaq.com/EA167 EA167 Dual Reference Adaptor] can convert most three electrode potentiostats into a four-electrode system.

== Galvanostats ==

Some potentiostats can be operated as galvanostats. In this case the current flow is controlled while the potential is monitored. Note that you cannot control both the current and the potential simultaneously unless you have a variable load! eDAQ potentiostats that work as galvanostats are:

: [http://www.edaq.com/ER467 ER467 High Current Potentiostat]
: [http://www.edaq.com/ER466 ER466 Integrated Potentiostat]
: [http://www.edaq.com/EA163 EA163 Potentiostat] (as well as its EA161 and EA160 predecessors)

== Software ==

Stand-alone potentiostats can be operated without a computer, and while there are a few models on the market, most modern potentiostats are operated via software from a computer.

Check that the software offers the [https://www.edaq.com/wiki/Software_for_Electrochemistry_Techniques electrochemistry techniques] you require, or whether you need extra, optional software. Often overlooked is the ease of operation of the software, and especially how the software saves experiments to the computer hard disk. For example, if each separate experiment is saved as a separate file then you will soon have hundreds of files on the computer hard disk to sort through every time you need to review a result. Some software offers library functions to do this while other software can multiple experiment into a single disk file for ease of access.

== eDAQ Potentiostat Systems ==

eDAQ offer a variety of potentiostat systems for a variety of experimental requirements. The table below gives an indication of these.

{| class="wikitable"
! width="50"|Name
! width="250"|[http://www.edaq.com/ER461 EChem Startup System]
! width="250"|[http://www.edaq.com/EA163 EChem Startup System with High Bandwidth Potentiostat]
! width="250"|[http://www.edaq.com/EA362 Dual Picostat Bundle]
! width="250"|[http://www.edaq.com/ER7005 QuadStat Bundle]
|-
| Product Code || align="center" | ER461CE || align="center" | ER7163 || align="center" | ER7162 || align="center" | ER7005
|- valign="top"
| Products Included ||
* [http://www.edaq.com/ER466 ER466]
* [http://www.edaq.com/ET014 ET014]
* [http://www.edaq.com/ES260 ES260]
* [http://www.edaq.com/ES500 ES500]
||
* [http://www.edaq.com/EA163 EA163]
* [http://www.edaq.com/ED410 ED410]
* [http://www.edaq.com/ET014 ET014]
* [http://www.edaq.com/ES260 ES260]
* [http://www.edaq.com/ES500 ES500]
||
* [http://www.edaq.com/EA362 EA362]
* [http://www.edaq.com/ED410 ED410]
* [http://www.edaq.com/ET014 ET014]
* [http://www.edaq.com/ES260 ES260]
* [http://www.edaq.com/ES500 ES500]
||
* [http://www.edaq.com/EA164 EA164]
* [http://www.edaq.com/ED821 ED821]
* [http://www.edaq.com/ER175 ER175]
* [http://www.edaq.com/ES500 ES500]
|-
| Number of Channels || align="center" | 1 || align="center" | 1 || align="center" | 2 (bipotentiostat) || align="center" | 4 (quadpotentiostat)
|- valign="top"
| Modes
||
* Potentiostat
* Galvanostat
* ZRA
* High Z
||
* Potentiostat
* Galvanostat
* ZRA
* High Z
||
* Potentiostat
* ZRA
||
* Potentiostat
* ZRA
|- valign="top"
| Current Ranges
||
±100*, 50, 20, 10, 5, 2, 1 mA

±500, 200, 100, 50, 20, 10, 5, 2, 1 µA

±500, 200, 100, 50, 20 nA


-* The [http://www.edaq.com/ER467 ER467] has a maximum current of 1 amp.

||
±100, 50, 20, 10, 5, 2, 1 mA

±500, 200, 100, 50, 20, 10, 5, 2, 1 µA

±500, 200, 100, 50, 20 nA
||

±10, 5, 2, 1 µA

±500, 200, 100, 50, 20, 10, 5, 2, 1 nA

±500, 200, 100, 50, 20, 10, 5, 2, 1 pA
||
±10, 5, 2, 1 mA

±500, 200, 100, 50, 20, 10, 5, 2, 1 µA

±500, 200, 100, 50, 20, 10, 5, 2, 1 nA

±500, 200 pA


|- valign="top"
| Electrochemistry Techniques
||

CV, LSV, DPV, SWV, NPV, RPV, LSSV, DPSV, SWSV, NPSV, MPV, DPA, CPE, DNPV, DBPV, CNA, CNC, CNP, PSA, CTPE, CCE, electrosynthesis, RDE*, QCM*, OCP/OCV, CCC

||

CV, LSV, DPV, SWV, NPV, RPV, LSSV, DPSV, SWSV, NPSV, MPV, DPA, CPE, DNPV, DBPV, CNA, CNC, CNP, CTPE, CCE, electrosynthesis, RDE*, QCM*, OCP/OCV, CCC

||

CV, LSV, DPV, SWV, NPV, RPV, LSSV, DPSV, SWSV, NPSV, MPV, DPA, CPE, DNPV, DBPV, CNA, CNC, CNP, CTPE, CCE, electrosynthesis, RDE*, QCM*, CCC

||

CNA, CNC, CNP, CTPE, CCE, electrosynthesis, RDE*, QCM*, CCC

CV and LSV with Chart software

|- valign="top"
| Typical Applications
||

* Compound characterization
* Electrolysis
* Analytical chemistry
* Kinetics
* [http://www.edaq.com/biosensors Sensors]

||

* Compound characterization
* Electrolysis
* Analytical chemistry
* Kinetics
* [http://www.edaq.com/biosensors Sensors]

||

* Carbon fiber and ultramicroelectrodes
* In vivo monitoring of dopamine
* Ionic transport across membranes or immiscible interfaces
* Monitor [http://www.edaq.com/dissolved-oxygen dissolved oxygen], [http://www.edaq.com/nitric-oxide nitric oxide], etc.

||

* [http://www.edaq.com/biosensors Simultaneous monitoring of sensors]
* Bipotentiostat operation
* [http://www.edaq.com/neurochemistry Neurochemistry]

|}

'''Acronyms for Electrochemistry Techniques'''

CV cyclic voltammetry; LSV linear sweep voltammetry; DPV differential pulse voltammetry; SWV square wave voltammetry; NPV normal pulse voltammetry; RPV reverse pulse voltammetry; LSSV linear sweep stripping voltammetry; DPSV differential pulse stripping voltammetry; SWSV square wave stripping voltammetry; NPSV normal pulse stripping voltammetry; MPV multipulse voltammetry; DPA differential pulse amperometry and double pulse amperometry; CPE constant potential electrolysis, DNPV differential normal pulse amperometry; DBPV double pulse voltammetry;

CNA chronoamperometry; CNC chronocoulometry; CNP chronopotentiometry; [https://www.edaq.com/wiki/Potentiometric_Stripping_Analysis_(PSA) PSA potentiometric stripping analysis]; CTPE controlled potential electrolysis; CCE controlled current electrolysis; RDE rotating disk electrode*; QCM quartz crystal microbalance*; OCP/OCV open circuit potential/open circuit voltage (High Z mode, high impedance voltmeter); CCC closed circuit current (ZRA mode, zero resistance ammeter)

RDE and QCM require additional third party equipment*

How to Choose a Potentiostat

2020-02-12T04:13:31Z

Oliver: /* eDAQ Potentiostat Systems */

A potentiostat is a device that controls the potential between a pair of electrodes whilst measuring the resulting current flow.

== Operating Requirements ==

When choosing a potentiostat you need to have some idea of the voltage and current limits within which you wish to operate.

Most potentiostats offer applied potentials (voltages) of up to ±10 V. Sensitive potentiostats designed for accurate measuring of small currents (nanoamperes or less) typically offer maximum currents of up to 10 mA. Large current potentiostats (1 A or more) often do not provide small current ranges (less than microamperes), or else they are very expensive, or require 'headstage' current amplifiers. Analytical chemists usually require a mid-range potentiostat (nanoamperes to 100 mA or so). Electrosynthesis experiments usually require currents in excess of 10 mA, and a maximum current of 1 A, or more, is often useful if you need to generate a few grams of material in a reasonable timeframe.

== Number of Electrodes ==

=== Two-Electrode Potentiostats ===

A two-electrode potentiostat uses a working and counter electrode. A disadvantage of this arrangement is that if the electrodes are further apart than the resistance between them increases and the current decreases. Thus reproducible results can be hard to achieve if electrode surface area, or separation distance, varies. Polarographic oxygen, peroxide, and nitric oxide electrode meters are all examples of two-electrode potentiostats. Note that in each of these cases the electrodes (anode and cathode) are usually built into a single probe body so that the orientation and distance between the electrodes is held constant from one experiment to the next.

eDAQ two-electrode potentiostats are:

: [http://www.edaq.com/EPU352 EPU352 USB Biosensor isoPod]
: [http://www.edaq.com/EPU354 EPU354 USB dO2 isoPod]
: [http://www.edaq.com/EPU355 EPU355 USB Nitric Oxide isoPod]

: [http://www.edaq.com/EP352 EP352 Biosensor isoPod] for use with e-corder systems
: [http://www.edaq.com/EP354 EP354 USB dO2 isoPod] for use with e-corder systems
: [http://www.edaq.com/EP355 EP355 USB Nitric Oxide isoPod] for use with e-corder systems

Three- and four-electrode potentiostats can often be used as two-electrode potentiostats by connecting the voltage sensing (reference electrode) inputs to the appropriate current passing (auxiliary or working electrode) inputs, see below.

=== Three-Electrode Potentiostats ===

This is typically what people mean when they say a 'potentiostat'. With a 'three-electrode' potentiostat the potential is monitored between reference and working electrodes that are in close proximity, while the potential of a relatively distant auxiliary electrode is adjusted. The current flow is measured between the working and auxiliary electrodes. This has the advantage that no current actually passes through the reference electrode, so there is no electrolytic reaction occurring there, and thus the reference electrode potential can remain constant throughout the experiment. A consequence of this arrangement is that the potential between the working and auxiliary electrodes (the 'compliance' potential, which is usually not reported) can be many times the applied potential (depending on electrolyte resistance and distance between the electrodes). By attaching the potentiostat reference and auxiliary inputs to the same 'counter' electrode, a three-electrode potentiostat can be used as a two-electrode potentiostat. The following eDAQ Potentiostats below can be operated as three-electrode potentiostats.

: [http://www.edaq.com/ER466 ER466 Integrated Potentiostat]
: [http://www.edaq.com/ER467 ER467 High Current Potentiostat]
: [http://www.edaq.com/EA163 EA163 Potentiostat]
: [http://www.edaq.com/ER466 EA164 QuadStat]
: [http://www.edaq.com/EA362 EA362 Dual Picostat]

=== Bipotentiostats and Multiple Working Electrodes ===

A bipotentiostat system features a reference and auxiliary electrode, and two working electrodes, whose potentials can be independently adjusted while the current flowing through them is monitored. This principle can be extended to any number of working electrodes, for example the
: [http://www.edaq.com/EA164 EA164 QuadStat] controls up to four working electrodes, while the
: [http://www.edaq.com/EA362 EA362 Dual Picostat] is a bipotentiostat (ie can control up to two working electrodes).

Typically the potential between the reference and first working electrode is controlled and the potentials of subsequent working electrodes are offset relative to the first electrode to achieve the desired effect. These potentiostats are often used in 'electrochemical nose' systems.

=== Four-Electrode Potentiostats ===

The term 'four-electrode potentiostat' is usually reserved for a device with two reference ('voltage sensing') electrodes and two working ('current passing') electrodes. The potential difference between the two reference electrodes is controlled while the current flow between the two working electrodes is monitored. These potentiostats are commonly used to measure the current flow across a membrane separating two compartments, or across the interface of two immiscible solvents (an [http://en.wikipedia.org/wiki/ITIES ITIES] experiment). The
: [http://www.edaq.com/ER467 ER467 High Current Potentiostat] is a 4-electrode system with one working, one counter, and two reference electrodes for the measurement of currents across membranes (4-electrode voltage clamp), or the interface between two immiscible electrolyte solutions (ITES).
: [http://www.edaq.com/EA362 EA362 Dual Picostat] can be used in four-electrode mode
: [http://www.edaq.com/EA167 EA167 Dual Reference Adaptor] can convert most three electrode potentiostats into a four-electrode system.

== Galvanostats ==

Some potentiostats can be operated as galvanostats. In this case the current flow is controlled while the potential is monitored. Note that you cannot control both the current and the potential simultaneously unless you have a variable load! eDAQ potentiostats that work as galvanostats are:

: [http://www.edaq.com/ER467 ER467 High Current Potentiostat]
: [http://www.edaq.com/ER466 ER466 Integrated Potentiostat]
: [http://www.edaq.com/EA163 EA163 Potentiostat] (as well as its EA161 and EA160 predecessors)

== Software ==

Stand-alone potentiostats can be operated without a computer, and while there are a few models on the market, most modern potentiostats are operated via software from a computer.

Check that the software offers the [https://www.edaq.com/wiki/Software_for_Electrochemistry_Techniques electrochemistry techniques] you require, or whether you need extra, optional software. Often overlooked is the ease of operation of the software, and especially how the software saves experiments to the computer hard disk. For example, if each separate experiment is saved as a separate file then you will soon have hundreds of files on the computer hard disk to sort through every time you need to review a result. Some software offers library functions to do this while other software can multiple experiment into a single disk file for ease of access.

== eDAQ Potentiostat Systems ==

eDAQ offer a variety of potentiostat systems for a variety of experimental requirements. The table below gives an indication of these.

{| class="wikitable"
! width="50"|Name
! width="250"|[http://www.edaq.com/ER461 EChem Startup System]
! width="250"|[http://www.edaq.com/EA163 EChem Startup System with High Bandwidth Potentiostat]
! width="250"|[http://www.edaq.com/EA362 Dual Picostat Bundle]
! width="250"|[http://www.edaq.com/ER7005 QuadStat Bundle]
|-
| Product Code || align="center" | ER461CE || align="center" | ER7163 || align="center" | ER7162 || align="center" | ER7005 || align="center" | ERZ101
|- valign="top"
| Products Included ||
* [http://www.edaq.com/ER466 ER466]
* [http://www.edaq.com/ET014 ET014]
* [http://www.edaq.com/ES260 ES260]
* [http://www.edaq.com/ES500 ES500]
||
* [http://www.edaq.com/EA163 EA163]
* [http://www.edaq.com/ED410 ED410]
* [http://www.edaq.com/ET014 ET014]
* [http://www.edaq.com/ES260 ES260]
* [http://www.edaq.com/ES500 ES500]
||
* [http://www.edaq.com/EA362 EA362]
* [http://www.edaq.com/ED410 ED410]
* [http://www.edaq.com/ET014 ET014]
* [http://www.edaq.com/ES260 ES260]
* [http://www.edaq.com/ES500 ES500]
||
* [http://www.edaq.com/EA164 EA164]
* [http://www.edaq.com/ED821 ED821]
* [http://www.edaq.com/ER175 ER175]
* [http://www.edaq.com/ES500 ES500]
|-
| Number of Channels || align="center" | 1 || align="center" | 1 || align="center" | 2 (bipotentiostat) || align="center" | 4 (quadpotentiostat)
|- valign="top"
| Modes
||
* Potentiostat
* Galvanostat
* ZRA
* High Z
||
* Potentiostat
* Galvanostat
* ZRA
* High Z
||
* Potentiostat
* ZRA
||
* Potentiostat
* ZRA
|- valign="top"
| Current Ranges
||
±100*, 50, 20, 10, 5, 2, 1 mA

±500, 200, 100, 50, 20, 10, 5, 2, 1 µA

±500, 200, 100, 50, 20 nA


-* The [http://www.edaq.com/ER467 ER467] has a maximum current of 1 amp.

||
±100, 50, 20, 10, 5, 2, 1 mA

±500, 200, 100, 50, 20, 10, 5, 2, 1 µA

±500, 200, 100, 50, 20 nA
||

±10, 5, 2, 1 µA

±500, 200, 100, 50, 20, 10, 5, 2, 1 nA

±500, 200, 100, 50, 20, 10, 5, 2, 1 pA
||
±10, 5, 2, 1 mA

±500, 200, 100, 50, 20, 10, 5, 2, 1 µA

±500, 200, 100, 50, 20, 10, 5, 2, 1 nA

±500, 200 pA


|- valign="top"
| Electrochemistry Techniques
||

CV, LSV, DPV, SWV, NPV, RPV, LSSV, DPSV, SWSV, NPSV, MPV, DPA, CPE, DNPV, DBPV, CNA, CNC, CNP, PSA, CTPE, CCE, electrosynthesis, RDE*, QCM*, OCP/OCV, CCC

||

CV, LSV, DPV, SWV, NPV, RPV, LSSV, DPSV, SWSV, NPSV, MPV, DPA, CPE, DNPV, DBPV, CNA, CNC, CNP, CTPE, CCE, electrosynthesis, RDE*, QCM*, OCP/OCV, CCC

||

CV, LSV, DPV, SWV, NPV, RPV, LSSV, DPSV, SWSV, NPSV, MPV, DPA, CPE, DNPV, DBPV, CNA, CNC, CNP, CTPE, CCE, electrosynthesis, RDE*, QCM*, CCC

||

CNA, CNC, CNP, CTPE, CCE, electrosynthesis, RDE*, QCM*, CCC

CV and LSV with Chart software

|- valign="top"
| Typical Applications
||

* Compound characterization
* Electrolysis
* Analytical chemistry
* Kinetics
* [http://www.edaq.com/biosensors Sensors]

||

* Compound characterization
* Electrolysis
* Analytical chemistry
* Kinetics
* [http://www.edaq.com/biosensors Sensors]

||

* Carbon fiber and ultramicroelectrodes
* In vivo monitoring of dopamine
* Ionic transport across membranes or immiscible interfaces
* Monitor [http://www.edaq.com/dissolved-oxygen dissolved oxygen], [http://www.edaq.com/nitric-oxide nitric oxide], etc.

||

* [http://www.edaq.com/biosensors Simultaneous monitoring of sensors]
* Bipotentiostat operation
* [http://www.edaq.com/neurochemistry Neurochemistry]

|}

'''Acronyms for Electrochemistry Techniques'''

CV cyclic voltammetry; LSV linear sweep voltammetry; DPV differential pulse voltammetry; SWV square wave voltammetry; NPV normal pulse voltammetry; RPV reverse pulse voltammetry; LSSV linear sweep stripping voltammetry; DPSV differential pulse stripping voltammetry; SWSV square wave stripping voltammetry; NPSV normal pulse stripping voltammetry; MPV multipulse voltammetry; DPA differential pulse amperometry and double pulse amperometry; CPE constant potential electrolysis, DNPV differential normal pulse amperometry; DBPV double pulse voltammetry;

CNA chronoamperometry; CNC chronocoulometry; CNP chronopotentiometry; [https://www.edaq.com/wiki/Potentiometric_Stripping_Analysis_(PSA) PSA potentiometric stripping analysis]; CTPE controlled potential electrolysis; CCE controlled current electrolysis; RDE rotating disk electrode*; QCM quartz crystal microbalance*; OCP/OCV open circuit potential/open circuit voltage (High Z mode, high impedance voltmeter); CCC closed circuit current (ZRA mode, zero resistance ammeter)

RDE and QCM require additional third party equipment*

Troubleshooting Communication between Hardware and Computer, Hardware Unavailable, Cannot Find a Hardware Unit

2020-02-12T04:08:36Z

Oliver: Undo revision 5029 by Oliver (talk)

=== Introduction ===

When you launch any eDAQ software, the software will normally check to see if any eDAQ hardware is connected to the computer and turned on, and then the software will try to communicate with it. If the software cannot communicate with any eDAQ hardware, it will show one of the following messages:

* Hardware Unit Unavailable, Chart is unable to find a Hardware Unit. (in Chart software)
* Hardware Unavailable, Cannot find a hardware unit (in EChem and Scope software)
* Hardware Unavailable, Cannot find a recording unit (in PowerChrom software)
* Z100 Navigator, No device found (in Z100 Navigator software)
* Device Selector, Please select a C4D device (in C4D Profiler V2 software)
* Device Selection, Unable to detect any ER430 HV Sequencer units. (in QuadSequencer Software)

{|
| [[File:Hardware Unit Unavailable, Chart is unable to find a Hardware Unit. (in Chart software).jpg|300px|thumb|right|Chart software]]
| [[File:Hardware Unavailable, Cannot find a hardware unit (in EChem and Scope software).jpg|300px|thumb|right|EChem and Scope software]]
| [[File:Hardware Unavailable, Cannot find a recording unit (in PowerChrom software).jpg|300px|thumb|right|PowerChrom software]]
|}

{|
| [[File:Z100 Navigator, No device found (Z100 Navigator).jpg|300px|thumb|right|Z100 Navigator software]]
| [[File:Device Selector, Please select a C4D device (C4D Profiler V2).jpg|300px|thumb|right|C4D Profiler V2 software]]
| [[File:Device Selection, Unable to detect any ER430 HV Sequencer units. (QuadSequencer Software).jpg|300px|thumb|right|QuadSequencer software]]
|}

=== Analysis Mode ===

You may want to continue in Analysis Mode. This lets you view a previously saved data file, analyse your data and save the data file, but you won't be able to communicate with any hardware or collect new data.

If you want to collect new data, you need the software to communicate with the hardware.

Note: To always run in Analysis mode.
You may want to install the eDAQ software on a computer that will never be used to run experiments on. Maybe it’s a computer outside the lab, in your office or a personal laptop, on which you only want to view and analyse the data you collected in the lab. You can set the software so that, each time it’s launched, it won't check to see if eDAQ hardware is connected to the computer. You can set this by:
* In Chart software, go to the menu Edit, select Preferences, Hardware Unit Startup, and click Always start in analysis mode
* In PowerChrom software, go to the menu Edit, select Preferences, Hardware-Startup and click Always start in analysis mode

=== Check List ===

Perform the checks listed below. DON’T MISS ANY STEPS until your problem is solved!
# Check the '''hardware unit is turned on!''' Make sure that the LEDs on the front of the hardware unit are lit. If you see red LEDs flashing on the front of the hardware unit, turn the hardware unit off and on to see if that clears the problem. If the red LEDs are still there, there is something wrong with the unit; please contact eDAQ.
# The '''USB cable''':
#* Make sure the USB cable is '''connected''' to the computer and to the hardware.
#* Try a '''different USB cable'''. USB cables can break or become intermittent, so it’s a good idea to try a different one. eDAQ equipment uses either the standard USB cable used by other electronic devices like printers, or the mini USB cable, so you should be able to borrow a cable from a different device.
#* Connect the eDAQ hardware to a '''different USB connector''' on the computer. The computer might have a faulty USB port. USB ports on the front of a desktop PC can be a bit more troublesome, due to the extension leads used to connect them to the motherboard; try connecting to the back of the computer. Windows can also get confused, and refuse to have that device on a particular USB port (at least until the next reboot).
#* If you are using a '''USB hub''', try connecting the eDAQ hardware directly to the USB connector on the computer. The USB hub might be interrupting the communication.
# '''Reinstall the eDAQ software''', to ensure the latest version of the driver is installed. Don’t rely on using the software that came with the equipment. Older software versions won't be able to work with new hardware. Make sure you are installing the latest version of the software downloaded from the [https://www.edaq.com/software-downloads software download webpage].
#* turn the hardware off
#* reinstalling the eDAQ software for that device
#* turn the hardware on
#* it may take Windows a 2-3 minutes to find and install the driver correctly.
# Try a '''different computer'''. A virus on a computer, or a particular setting on a computer, can stop the communication to the eDAQ hardware. Try installing the eDAQ software on a different computer and connecting the eDAQ hardware to that computer, to see if the same problem occurs.
# Make sure that Windows is using the '''correct driver''' for eDAQ hardware. Do this by:
## Press the Windows key on your keyboard (or click the Start button) and type ''Device Manager''.
## In the Device Manager window, find your eDAQ hardware; it might be under the headings “eDAQ e-corders” or “Ports (COM & LPT)”. If there is a problem, it may show under Universal Serial Bus controllers or other devices.
## Hover the mouse pointer over the eDAQ hardware and right click the mouse; select “Properties”. A window will open and will give you information in the "Device status" section.
## If the issue is that the driver is missing (it will have a yellow triangle on the icon in Device Manager):
## Let Windows try to find the driver (will only work after installing the eDAQ software for the device):
##* right-click on the device
##* choose "Update driver"
##* select the "Search automatically" option
##* Wait 2-3 minutes for Windows to find and install the driver
## If that doesn't work, manually install the driver:
##* First get the standalone copy of the driver files. These can be found on the eDAQ software install USB sticks, and in the [https://www.edaq.com/utilities-tools "Utilities and Tools"] section of the eDAQ website.
##* If the download is an "exe" file, then:
##** Turn off your device
##** Run the "exe", to install the drivers
##** Turn the device on, and wait 2-3 minutes for Windows to install and configure it.
##* If the download is a ZIP file with an "inf" file in it:
##** Extract the ZIP file's contents
##** Right-click on the device in device manager
##** choose "Update driver"
##** Select the "Browse my computer for driver software" option
##** Browse to the extracted files, select the folder/INF file
##** It may take Windows a 2-3 minutes to then install the driver
# If you are using eDAQ hardware that has virtual serial protocol (such as the USB isoPods, the ER815 and ER825 C4D Detectors or the ER430 High Voltage Sequencer) try see if you can communicate with the hardware using terminal emulation software compatible with serial (COM) ports (for example, [http://logmett.com Tera Term] or [https://www.hilgraeve.com HyperTerminal])
# If none of the above suggestions solve your problem, please could you fill in with as MANY DETAILS as possible, the [http://www.edaq.com/technical-help-request Technical Help Request form]. Let us know what you tried from the instructions on this page, and what did/didn't happen.

Troubleshooting Communication between Hardware and Computer, Hardware Unavailable, Cannot Find a Hardware Unit

2020-02-12T04:07:42Z

Oliver:

=== Introduction ===

When you launch any eDAQ software, the software will normally check to see if any eDAQ hardware is connected to the computer and turned on, and then the software will try to communicate with it. If the software cannot communicate with any eDAQ hardware, it will show one of the following messages:

* Hardware Unit Unavailable, Chart is unable to find a Hardware Unit. (in Chart software)
* Hardware Unavailable, Cannot find a hardware unit (in EChem and Scope software)
* Hardware Unavailable, Cannot find a recording unit (in PowerChrom software)
* Device Selector, Please select a C4D device (in C4D Profiler V2 software)
* Device Selection, Unable to detect any ER430 HV Sequencer units. (in QuadSequencer Software)

{|
| [[File:Hardware Unit Unavailable, Chart is unable to find a Hardware Unit. (in Chart software).jpg|300px|thumb|right|Chart software]]
| [[File:Hardware Unavailable, Cannot find a hardware unit (in EChem and Scope software).jpg|300px|thumb|right|EChem and Scope software]]
| [[File:Hardware Unavailable, Cannot find a recording unit (in PowerChrom software).jpg|300px|thumb|right|PowerChrom software]]
|}

{|
| [[File:Device Selector, Please select a C4D device (C4D Profiler V2).jpg|300px|thumb|right|C4D Profiler V2 software]]
| [[File:Device Selection, Unable to detect any ER430 HV Sequencer units. (QuadSequencer Software).jpg|300px|thumb|right|QuadSequencer software]]
|}

=== Analysis Mode ===

You may want to continue in Analysis Mode. This lets you view a previously saved data file, analyse your data and save the data file, but you won't be able to communicate with any hardware or collect new data.

If you want to collect new data, you need the software to communicate with the hardware.

Note: To always run in Analysis mode.
You may want to install the eDAQ software on a computer that will never be used to run experiments on. Maybe it’s a computer outside the lab, in your office or a personal laptop, on which you only want to view and analyse the data you collected in the lab. You can set the software so that, each time it’s launched, it won't check to see if eDAQ hardware is connected to the computer. You can set this by:
* In Chart software, go to the menu Edit, select Preferences, Hardware Unit Startup, and click Always start in analysis mode
* In PowerChrom software, go to the menu Edit, select Preferences, Hardware-Startup and click Always start in analysis mode

=== Check List ===

Perform the checks listed below. DON’T MISS ANY STEPS until your problem is solved!
# Check the '''hardware unit is turned on!''' Make sure that the LEDs on the front of the hardware unit are lit. If you see red LEDs flashing on the front of the hardware unit, turn the hardware unit off and on to see if that clears the problem. If the red LEDs are still there, there is something wrong with the unit; please contact eDAQ.
# The '''USB cable''':
#* Make sure the USB cable is '''connected''' to the computer and to the hardware.
#* Try a '''different USB cable'''. USB cables can break or become intermittent, so it’s a good idea to try a different one. eDAQ equipment uses either the standard USB cable used by other electronic devices like printers, or the mini USB cable, so you should be able to borrow a cable from a different device.
#* Connect the eDAQ hardware to a '''different USB connector''' on the computer. The computer might have a faulty USB port. USB ports on the front of a desktop PC can be a bit more troublesome, due to the extension leads used to connect them to the motherboard; try connecting to the back of the computer. Windows can also get confused, and refuse to have that device on a particular USB port (at least until the next reboot).
#* If you are using a '''USB hub''', try connecting the eDAQ hardware directly to the USB connector on the computer. The USB hub might be interrupting the communication.
# '''Reinstall the eDAQ software''', to ensure the latest version of the driver is installed. Don’t rely on using the software that came with the equipment. Older software versions won't be able to work with new hardware. Make sure you are installing the latest version of the software downloaded from the [https://www.edaq.com/software-downloads software download webpage].
#* turn the hardware off
#* reinstalling the eDAQ software for that device
#* turn the hardware on
#* it may take Windows a 2-3 minutes to find and install the driver correctly.
# Try a '''different computer'''. A virus on a computer, or a particular setting on a computer, can stop the communication to the eDAQ hardware. Try installing the eDAQ software on a different computer and connecting the eDAQ hardware to that computer, to see if the same problem occurs.
# Make sure that Windows is using the '''correct driver''' for eDAQ hardware. Do this by:
## Press the Windows key on your keyboard (or click the Start button) and type ''Device Manager''.
## In the Device Manager window, find your eDAQ hardware; it might be under the headings “eDAQ e-corders” or “Ports (COM & LPT)”. If there is a problem, it may show under Universal Serial Bus controllers or other devices.
## Hover the mouse pointer over the eDAQ hardware and right click the mouse; select “Properties”. A window will open and will give you information in the "Device status" section.
## If the issue is that the driver is missing (it will have a yellow triangle on the icon in Device Manager):
## Let Windows try to find the driver (will only work after installing the eDAQ software for the device):
##* right-click on the device
##* choose "Update driver"
##* select the "Search automatically" option
##* Wait 2-3 minutes for Windows to find and install the driver
## If that doesn't work, manually install the driver:
##* First get the standalone copy of the driver files. These can be found on the eDAQ software install USB sticks, and in the [https://www.edaq.com/utilities-tools "Utilities and Tools"] section of the eDAQ website.
##* If the download is an "exe" file, then:
##** Turn off your device
##** Run the "exe", to install the drivers
##** Turn the device on, and wait 2-3 minutes for Windows to install and configure it.
##* If the download is a ZIP file with an "inf" file in it:
##** Extract the ZIP file's contents
##** Right-click on the device in device manager
##** choose "Update driver"
##** Select the "Browse my computer for driver software" option
##** Browse to the extracted files, select the folder/INF file
##** It may take Windows a 2-3 minutes to then install the driver
# If you are using eDAQ hardware that has virtual serial protocol (such as the USB isoPods, the ER815 and ER825 C4D Detectors or the ER430 High Voltage Sequencer) try see if you can communicate with the hardware using terminal emulation software compatible with serial (COM) ports (for example, [http://logmett.com Tera Term] or [https://www.hilgraeve.com HyperTerminal])
# If none of the above suggestions solve your problem, please could you fill in with as MANY DETAILS as possible, the [http://www.edaq.com/technical-help-request Technical Help Request form]. Let us know what you tried from the instructions on this page, and what did/didn't happen.

Screencast Training Videos

2020-02-12T04:00:39Z

Oliver:

== Electrochemistry ==

[[File:pd-shows-ess-kit-thumb.jpg|90px|left|link=Setting_up_the_EChem_Startup_System]]

[[Setting up the EChem Startup System]]

[[File:Echem-potentiostat-maintenance.jpg|90px|left|link=Check_the_Performance_of_the_Potentiostat_with_Potentiostat_Maintenance_Check]]

[[Check the Performance of the Potentiostat with Potentiostat Maintenance Check]]

[[File:Setting-up-EChem-software-for-Cyclic-Voltammetry.jpg|90px|left|link=How_to_Setup_the_EChem_Software_for_Cyclic_Voltammetry]]

[[How to Setup the EChem Software for Cyclic Voltammetry]]

[[File:Chronoamperometry.jpg|90px|left|link=How_to_Setup_the_Chart_Software_for_Chronoamperometry]]

[[How to Setup the Chart Software for Chronoamperometry]]

[[File:Galvanostat mode3.jpg|90px|left|link=Using_the_eDAQ_Potentiostat_in_Galvanostat_Mode]]

[[Using the eDAQ Potentiostat in Galvanostat Mode]]

[[File:Echem drawing baseline.jpg|90px|left|link=How_to_Draw_a_Baseline_and_Integrate_a_Peak_in_the_EChem_Software]]

[[How to Draw a Baseline and Integrate a Peak in the EChem Software]]

[[File:Overlay-in-echem.jpg|90px|left|link=Overlaying_Voltammograms_in_EChem_Software]]

[[Overlaying Voltammograms in EChem Software]]

[[File:Echem-computed-funtions.jpg|90px|left|link=Computed_Functions_in_EChem_for_Data_Calculations_and_Smoothing]]

[[Computed Functions in EChem for Data Calculations and Smoothing]]

[[File:EChem-copy-and-paste.jpg|90px|left|link=How_to_Copy_and_Paste_EChem_Data_to_Other_Software]]

[[How to Copy and Paste EChem Data to Other Software]]

[[File:IV curve solar cell4.JPG|90px|left|link=IV_Curve_of_a_Solar_Cell_in_EChem_Software]]

[[IV Curve of a Solar Cell in EChem Software]]

== C4D Conductivity Detector ==

[[File:C4d-procedure-powerchrom.jpg|90px|left|link=A_Procedure_for_C4D_Analysis_in_PowerChrom_Software]]

[[A Procedure for C4D Analysis in PowerChrom Software]]

[[File:C4D Profiler V2 Software to Optimise C4D Settings, thumb.jpg|90px|left|link=C4D Profiler_V2_Software_to_Optimise_C4D_Settings]]

[[C4D Profiler V2 Software to Optimise C4D Settings]]

[[File:C4D Configurator Software thumb.jpg|90px|left|link=Configurator_Software_to_select_C4D_Settings_with_ER815_and_ER825_with Serial_Firmware]]

[[C4D Configurator Software]], to configure C4D Settings in the ER815 and ER825 with Serial Firmware

[[File:Trigger-in-mce.jpg|90px|left|link=HV_Sequencer_to_Trigger_PowerChrom_Software_in_Microchip_Electrophoresis]]

[[HV Sequencer to Trigger PowerChrom Software in Microchip Electrophoresis]]

[[File:Et225b.jpg|90px|left|link=A_Procedure_for_Microchip_Electrophoresis_with_C4D]]

[[A Procedure for Microchip Electrophoresis with C4D with the ET225 and ER455]]

[[File:QuadSequencer software Simulator, High Voltage Sequencer-02.jpg|90px|left|link=Simulator_Mode_in_QuadSequencer_Software]]

[[Simulator Mode in QuadSequencer Software]]

'''Obsolete Videos'''

[[File:C4d profiler in powerchrom,newicon.jpg|90px|left|link=The_C4D_Profiler_in_PowerChrom_Software_to_Optimise_C4D_Settings]]

obsolete video: [[The C4D Profiler in PowerChrom Software to Optimise C4D Settings]]

[[File:C4d-detector-software.jpg|90px|left|link=Using_the_C4D_Detector_Software_to_Control_the_ER125_C4D_Detector]]

for obsolete ER125 product: [[Using the C4D Detector Software to Control the ER125 C4D Detector]]

== Chart ==
==== Setting up the Software ====

[[File:Digital outputs.jpg|90px|left|link=Digital_Outputs_and_the_Event_Manager]]

[[Digital Outputs and the Event Manager]]

[[File:Stim-thumb.jpg|90px|left|link=Stimulator_Waveform_Generator]]

[[Stimulator Waveform Generator]]

[[File:Timed-and-multiple-add-to-data-pad.jpg|90px|left|link=Timed_and_Multiple_Add_to_Data_Pad]]

[[Timed and Multiple Add to Data Pad]]

==== Converting Units ====

[[File:Units-Conversion.jpg|90px|left|link=Units_Conversion]]

[[Units Conversion]]

[[File:Multipoint-Calibration.jpg|90px|left|link=Multipoint_Calibration]]

[[Multipoint Calibration]]

[[File:PH-Calibration.jpg|90px|left|link=PH_Calibration]]

[[pH Calibration]]

==== Analysing Data ====

[[File:Data-pad.jpg|90px|left|link=Data_Pad]]

[[Data Pad]]

[[File:Marker to calculate height of peak.jpg|90px|left|link=Marker_to_Calculate_Height_of_a_Peak]]

[[Marker to Calculate Height of a Peak]]

[[File:Spectrum-FFT.jpg|90px|left|link=Spectrum_FFT]]

[[Spectrum FFT]]

[[File:Baseline-adjustment-ext.jpg|90px|left|link=Baseline_Adjustment_Extension]]

[[Baseline Adjustment Extension]]

==== Saving, Importing and Exporting Data ====

[[File:Copy-and-Paste-Chart-Data-to-Other-Software.jpg|90px|left|link=Copy_and_Paste_Chart_Data_to_Other_Software]]

[[Copy and Paste Chart Data to Other Software]]

[[File:Chart-Save-As-screen.jpg|90px|left|link=Chart_Save_As]]

[[Chart Save As]]

[[File:Automatically-exporting-chart-data-into-excel.jpg|90px|left|link=Automatically_Exporting_Chart_data_into_Excel]]

[[Automatically Exporting Chart data into Excel]]

[[File:Open-PowerChrom-Data-in-the-Chart-Software.jpg|90px|left|link=Open_PowerChrom_Data_in_the_Chart_Software]]

[[Open PowerChrom Data in the Chart Software]]

== PowerChrom ==

[[File:PowerChrom-Settings.jpg|90px|left|link=Basic_Settings]]

[[Basic Settings]]

[[File:PowerChrom-Procedure-for-Recording-Data.jpg|90px|left|link=A_Simple_Analysis]]

[[A Simple Analysis]]

[[File:Powerchrom-baseline.jpg|90px|left|link=Manually_Integrate_a_Peak]]

[[Manually Integrate a Peak]]

[[File:Powerchrom-simple-procedure.jpg|90px|left|link=Method_and_Calibration_Tables]]

[[Method and Calibration Tables]]

[[File:Overlay-in-powerchrom.jpg|90px|left|link=Overlaying_Chromatographs]]

[[Overlaying Chromatographs]]

[[File:PowerChrom-copy-and-paste.jpg|90px|left|link=Copy_and_Paste_Data_to_Other_Softwares]]

[[Copy and Paste Data to Other Softwares]]

[[File:Open-a-Chart-Data-File-in-PowerChrom-Software.jpg|90px|left|link=Open_a_Chart_Data_File_in_PowerChrom_Software]]

[[Open a Chart Data File in PowerChrom Software]]

== FIA Flow Injection Analysis ==

[[File:Fia extension.jpg|90px|left|link=Integrate_a_Peak_and_Calibration_Curve]]

[[Integrate a Peak and Calibration Curve]]

[[File:Fia print.jpg|90px|left|link=Print_a_Report]]

[[Print a Report]]

== isoPods ==

[[File:Isopods-video-thumb.jpg|90px|left|link=The_isoPods_for_Recording_Temperature,_pH,_Conductivity_and_Dissolved_Oxygen]]

[[The isoPods for Recording Temperature, pH, Conductivity and Dissolved Oxygen]]

[[File:Serial-port-monitor2.jpg|90px|left|link=Serial_Port_Monitor]]

[[Serial Port Monitor]]

== Electrochemical Impedance Spectroscopy (EIS) ==

[[File:Z100-loopback-thumb.jpg|90px|left|link=Z100_Loopback_Test]]

[[Z100 Loopback Test]]

[[File:Z100-blank-test-thumb3.jpg|90px|left|link=Z100_Blank_Test]]

[[Z100 Blank Test]]

[[File:ZMAN basics.jpg|90px|left|link=ZMAN_Basic_Overview_of_ZMAN_software]]

[[ZMAN Basic Overview of ZMAN software]]

[[File:ZMAN1 open.jpg|90px|left|link=ZMAN1_Open_a_Data_File]]

[[ZMAN1 Open a Data File]]

[[File:ZMAN2 preview.jpg|90px|left|link=ZMAN2_Preview_and_Edit_Data]]

[[ZMAN2 Preview and Edit Data]]

[[File:ZMAN3 Kramers.jpg|90px|left|link=ZMAN3_Kramers-Kronig_Consistency]]

[[ZMAN3 Kramers-Kronig Consistency]]

[[File:ZMAN4 modeling.jpg|90px|left|link=ZMAN4_Modeling]]

[[ZMAN4 Modeling]]

[[File:ZMAN5 auto.jpg|90px|left|link=ZMAN5_Automatic_Model_Search]]

[[ZMAN5 Automatic Model Search]]

[[File:ZMAN6 circular.jpg|90px|left|link=ZMAN6_Circular_Fitting]]

[[ZMAN6 Circular Fitting]]

== SDx Tethered Membranes ==

[[File:Sdx1 thumb.jpg|90px|left|link=How_to_assemble_a_tethaPlate_cartridge]]

[[How to assemble a tethaPlate cartridge]]

[[File:Sdx2 thumb.jpg|90px|left|link=Making_a_tethered_membrane]]

[[Making a tethered membrane]]

Screencast Training Videos

2020-02-12T03:59:42Z

Oliver:

== Electrochemistry ==

[[File:pd-shows-ess-kit-thumb.jpg|90px|left|link=Setting_up_the_EChem_Startup_System]]

[[Setting up the EChem Startup System]]

[[File:Echem-potentiostat-maintenance.jpg|90px|left|link=Check_the_Performance_of_the_Potentiostat_with_Potentiostat_Maintenance_Check]]

[[Check the Performance of the Potentiostat with Potentiostat Maintenance Check]]

[[File:Setting-up-EChem-software-for-Cyclic-Voltammetry.jpg|90px|left|link=How_to_Setup_the_EChem_Software_for_Cyclic_Voltammetry]]

[[How to Setup the EChem Software for Cyclic Voltammetry]]

[[File:Chronoamperometry.jpg|90px|left|link=How_to_Setup_the_Chart_Software_for_Chronoamperometry]]

[[How to Setup the Chart Software for Chronoamperometry]]

[[File:Galvanostat mode3.jpg|90px|left|link=Using_the_eDAQ_Potentiostat_in_Galvanostat_Mode]]

[[Using the eDAQ Potentiostat in Galvanostat Mode]]

[[File:Echem drawing baseline.jpg|90px|left|link=How_to_Draw_a_Baseline_and_Integrate_a_Peak_in_the_EChem_Software]]

[[How to Draw a Baseline and Integrate a Peak in the EChem Software]]

[[File:Overlay-in-echem.jpg|90px|left|link=Overlaying_Voltammograms_in_EChem_Software]]

[[Overlaying Voltammograms in EChem Software]]

[[File:Echem-computed-funtions.jpg|90px|left|link=Computed_Functions_in_EChem_for_Data_Calculations_and_Smoothing]]

[[Computed Functions in EChem for Data Calculations and Smoothing]]

[[File:EChem-copy-and-paste.jpg|90px|left|link=How_to_Copy_and_Paste_EChem_Data_to_Other_Software]]

[[How to Copy and Paste EChem Data to Other Software]]

[[File:IV curve solar cell4.JPG|90px|left|link=IV_Curve_of_a_Solar_Cell_in_EChem_Software]]

[[IV Curve of a Solar Cell in EChem Software]]

== C4D Conductivity Detector ==

[[File:C4d-procedure-powerchrom.jpg|90px|left|link=A_Procedure_for_C4D_Analysis_in_PowerChrom_Software]]

[[A Procedure for C4D Analysis in PowerChrom Software]]

[[File:C4D Profiler V2 Software to Optimise C4D Settings, thumb.jpg|90px|left|link=C4D Profiler_V2_Software_to_Optimise_C4D_Settings]]

[[C4D Profiler V2 Software to Optimise C4D Settings]]

[[File:C4D Configurator Software thumb.jpg|90px|left|link=Configurator_Software_to_select_C4D_Settings_with_ER815_and_ER825_with Serial_Firmware]]

[[C4D Configurator Software]], to configure C4D Settings in the ER815 and ER825 with Serial Firmware

[[File:Trigger-in-mce.jpg|90px|left|link=HV_Sequencer_to_Trigger_PowerChrom_Software_in_Microchip_Electrophoresis]]

[[HV Sequencer to Trigger PowerChrom Software in Microchip Electrophoresis]]

[[File:Et225b.jpg|90px|left|link=A_Procedure_for_Microchip_Electrophoresis_with_C4D]]

[[A Procedure for Microchip Electrophoresis with C4D with the ET225 and ER455]]

[[File:QuadSequencer software Simulator, High Voltage Sequencer-02.jpg|90px|left|link=Simulator_Mode_in_QuadSequencer_Software]]

[[Simulator Mode in QuadSequencer Software]]

'''Obsolete Videos'''

[[File:C4d profiler in powerchrom,newicon.jpg|90px|left|link=The_C4D_Profiler_in_PowerChrom_Software_to_Optimise_C4D_Settings]]

obsolete video: [[The C4D Profiler in PowerChrom Software to Optimise C4D Settings]]

[[File:C4d-detector-software.jpg|90px|left|link=Using_the_C4D_Detector_Software_to_Control_the_ER125_C4D_Detector]]

for obsolete ER125 product: [[Using the C4D Detector Software to Control the ER125 C4D Detector]]

== Chart ==
==== Setting up the Software ====

[[File:Digital outputs.jpg|90px|left|link=Digital_Outputs_and_the_Event_Manager]]

[[Digital Outputs and the Event Manager]]

[[File:Stim-thumb.jpg|90px|left|link=Stimulator_Waveform_Generator]]

[[Stimulator Waveform Generator]]

[[File:Timed-and-multiple-add-to-data-pad.jpg|90px|left|link=Timed_and_Multiple_Add_to_Data_Pad]]

[[Timed and Multiple Add to Data Pad]]

==== Converting Units ====

[[File:Units-Conversion.jpg|90px|left|link=Units_Conversion]]

[[Units Conversion]]

[[File:Multipoint-Calibration.jpg|90px|left|link=Multipoint_Calibration]]

[[Multipoint Calibration]]

[[File:PH-Calibration.jpg|90px|left|link=PH_Calibration]]

[[pH Calibration]]

==== Analysing Data ====

[[File:Data-pad.jpg|90px|left|link=Data_Pad]]

[[Data Pad]]

[[File:Marker to calculate height of peak.jpg|90px|left|link=Marker_to_Calculate_Height_of_a_Peak]]

[[Marker to Calculate Height of a Peak]]

[[File:Spectrum-FFT.jpg|90px|left|link=Spectrum_FFT]]

[[Spectrum FFT]]

[[File:Baseline-adjustment-ext.jpg|90px|left|link=Baseline_Adjustment_Extension]]

[[Baseline Adjustment Extension]]

==== Saving, Importing and Exporting Data ====

[[File:Copy-and-Paste-Chart-Data-to-Other-Software.jpg|90px|left|link=Copy_and_Paste_Chart_Data_to_Other_Software]]

[[Copy and Paste Chart Data to Other Software]]

[[File:Chart-Save-As-screen.jpg|90px|left|link=Chart_Save_As]]

[[Chart Save As]]

[[File:Automatically-exporting-chart-data-into-excel.jpg|90px|left|link=Automatically_Exporting_Chart_data_into_Excel]]

[[Automatically Exporting Chart data into Excel]]

[[File:Open-PowerChrom-Data-in-the-Chart-Software.jpg|90px|left|link=Open_PowerChrom_Data_in_the_Chart_Software]]

[[Open PowerChrom Data in the Chart Software]]

== PowerChrom ==

[[File:PowerChrom-Settings.jpg|90px|left|link=Basic_Settings]]

[[Basic Settings]]

[[File:PowerChrom-Procedure-for-Recording-Data.jpg|90px|left|link=A_Simple_Analysis]]

[[A Simple Analysis]]

[[File:Powerchrom-baseline.jpg|90px|left|link=Manually_Integrate_a_Peak]]

[[Manually Integrate a Peak]]

[[File:Powerchrom-simple-procedure.jpg|90px|left|link=Method_and_Calibration_Tables]]

[[Method and Calibration Tables]]

[[File:Overlay-in-powerchrom.jpg|90px|left|link=Overlaying_Chromatographs]]

[[Overlaying Chromatographs]]

[[File:PowerChrom-copy-and-paste.jpg|90px|left|link=Copy_and_Paste_Data_to_Other_Softwares]]

[[Copy and Paste Data to Other Softwares]]

[[File:Open-a-Chart-Data-File-in-PowerChrom-Software.jpg|90px|left|link=Open_a_Chart_Data_File_in_PowerChrom_Software]]

[[Open a Chart Data File in PowerChrom Software]]

== SDx Tethered Membranes ==

[[File:Sdx1 thumb.jpg|90px|left|link=How_to_assemble_a_tethaPlate_cartridge]]

[[How to assemble a tethaPlate cartridge]]

[[File:Sdx2 thumb.jpg|90px|left|link=Making_a_tethered_membrane]]

[[Making a tethered membrane]]

== FIA Flow Injection Analysis ==

[[File:Fia extension.jpg|90px|left|link=Integrate_a_Peak_and_Calibration_Curve]]

[[Integrate a Peak and Calibration Curve]]

[[File:Fia print.jpg|90px|left|link=Print_a_Report]]

[[Print a Report]]

== isoPods ==

[[File:Isopods-video-thumb.jpg|90px|left|link=The_isoPods_for_Recording_Temperature,_pH,_Conductivity_and_Dissolved_Oxygen]]

[[The isoPods for Recording Temperature, pH, Conductivity and Dissolved Oxygen]]

[[File:Serial-port-monitor2.jpg|90px|left|link=Serial_Port_Monitor]]

[[Serial Port Monitor]]

== Electrochemical Impedance Spectroscopy (EIS) ==

[[File:Z100-loopback-thumb.jpg|90px|left|link=Z100_Loopback_Test]]

[[Z100 Loopback Test]]

[[File:Z100-blank-test-thumb3.jpg|90px|left|link=Z100_Blank_Test]]

[[Z100 Blank Test]]

[[File:ZMAN basics.jpg|90px|left|link=ZMAN_Basic_Overview_of_ZMAN_software]]

[[ZMAN Basic Overview of ZMAN software]]

[[File:ZMAN1 open.jpg|90px|left|link=ZMAN1_Open_a_Data_File]]

[[ZMAN1 Open a Data File]]

[[File:ZMAN2 preview.jpg|90px|left|link=ZMAN2_Preview_and_Edit_Data]]

[[ZMAN2 Preview and Edit Data]]

[[File:ZMAN3 Kramers.jpg|90px|left|link=ZMAN3_Kramers-Kronig_Consistency]]

[[ZMAN3 Kramers-Kronig Consistency]]

[[File:ZMAN4 modeling.jpg|90px|left|link=ZMAN4_Modeling]]

[[ZMAN4 Modeling]]

[[File:ZMAN5 auto.jpg|90px|left|link=ZMAN5_Automatic_Model_Search]]

[[ZMAN5 Automatic Model Search]]

[[File:ZMAN6 circular.jpg|90px|left|link=ZMAN6_Circular_Fitting]]

[[ZMAN6 Circular Fitting]]

Screencast Training Videos

2020-02-12T03:58:13Z

Oliver:

== Electrochemistry ==

[[File:pd-shows-ess-kit-thumb.jpg|90px|left|link=Setting_up_the_EChem_Startup_System]]

[[Setting up the EChem Startup System]]

[[File:Echem-potentiostat-maintenance.jpg|90px|left|link=Check_the_Performance_of_the_Potentiostat_with_Potentiostat_Maintenance_Check]]

[[Check the Performance of the Potentiostat with Potentiostat Maintenance Check]]

[[File:Setting-up-EChem-software-for-Cyclic-Voltammetry.jpg|90px|left|link=How_to_Setup_the_EChem_Software_for_Cyclic_Voltammetry]]

[[How to Setup the EChem Software for Cyclic Voltammetry]]

[[File:Chronoamperometry.jpg|90px|left|link=How_to_Setup_the_Chart_Software_for_Chronoamperometry]]

[[How to Setup the Chart Software for Chronoamperometry]]

[[File:Galvanostat mode3.jpg|90px|left|link=Using_the_eDAQ_Potentiostat_in_Galvanostat_Mode]]

[[Using the eDAQ Potentiostat in Galvanostat Mode]]

[[File:Echem drawing baseline.jpg|90px|left|link=How_to_Draw_a_Baseline_and_Integrate_a_Peak_in_the_EChem_Software]]

[[How to Draw a Baseline and Integrate a Peak in the EChem Software]]

[[File:Overlay-in-echem.jpg|90px|left|link=Overlaying_Voltammograms_in_EChem_Software]]

[[Overlaying Voltammograms in EChem Software]]

[[File:Echem-computed-funtions.jpg|90px|left|link=Computed_Functions_in_EChem_for_Data_Calculations_and_Smoothing]]

[[Computed Functions in EChem for Data Calculations and Smoothing]]

[[File:EChem-copy-and-paste.jpg|90px|left|link=How_to_Copy_and_Paste_EChem_Data_to_Other_Software]]

[[How to Copy and Paste EChem Data to Other Software]]

[[File:IV curve solar cell4.JPG|90px|left|link=IV_Curve_of_a_Solar_Cell_in_EChem_Software]]

[[IV Curve of a Solar Cell in EChem Software]]

== Chart ==
==== Setting up the Software ====

[[File:Digital outputs.jpg|90px|left|link=Digital_Outputs_and_the_Event_Manager]]

[[Digital Outputs and the Event Manager]]

[[File:Stim-thumb.jpg|90px|left|link=Stimulator_Waveform_Generator]]

[[Stimulator Waveform Generator]]

[[File:Timed-and-multiple-add-to-data-pad.jpg|90px|left|link=Timed_and_Multiple_Add_to_Data_Pad]]

[[Timed and Multiple Add to Data Pad]]

==== Converting Units ====

[[File:Units-Conversion.jpg|90px|left|link=Units_Conversion]]

[[Units Conversion]]

[[File:Multipoint-Calibration.jpg|90px|left|link=Multipoint_Calibration]]

[[Multipoint Calibration]]

[[File:PH-Calibration.jpg|90px|left|link=PH_Calibration]]

[[pH Calibration]]

==== Analysing Data ====

[[File:Data-pad.jpg|90px|left|link=Data_Pad]]

[[Data Pad]]

[[File:Marker to calculate height of peak.jpg|90px|left|link=Marker_to_Calculate_Height_of_a_Peak]]

[[Marker to Calculate Height of a Peak]]

[[File:Spectrum-FFT.jpg|90px|left|link=Spectrum_FFT]]

[[Spectrum FFT]]

[[File:Baseline-adjustment-ext.jpg|90px|left|link=Baseline_Adjustment_Extension]]

[[Baseline Adjustment Extension]]

==== Saving, Importing and Exporting Data ====

[[File:Copy-and-Paste-Chart-Data-to-Other-Software.jpg|90px|left|link=Copy_and_Paste_Chart_Data_to_Other_Software]]

[[Copy and Paste Chart Data to Other Software]]

[[File:Chart-Save-As-screen.jpg|90px|left|link=Chart_Save_As]]

[[Chart Save As]]

[[File:Automatically-exporting-chart-data-into-excel.jpg|90px|left|link=Automatically_Exporting_Chart_data_into_Excel]]

[[Automatically Exporting Chart data into Excel]]

[[File:Open-PowerChrom-Data-in-the-Chart-Software.jpg|90px|left|link=Open_PowerChrom_Data_in_the_Chart_Software]]

[[Open PowerChrom Data in the Chart Software]]

== PowerChrom ==

[[File:PowerChrom-Settings.jpg|90px|left|link=Basic_Settings]]

[[Basic Settings]]

[[File:PowerChrom-Procedure-for-Recording-Data.jpg|90px|left|link=A_Simple_Analysis]]

[[A Simple Analysis]]

[[File:Powerchrom-baseline.jpg|90px|left|link=Manually_Integrate_a_Peak]]

[[Manually Integrate a Peak]]

[[File:Powerchrom-simple-procedure.jpg|90px|left|link=Method_and_Calibration_Tables]]

[[Method and Calibration Tables]]

[[File:Overlay-in-powerchrom.jpg|90px|left|link=Overlaying_Chromatographs]]

[[Overlaying Chromatographs]]

[[File:PowerChrom-copy-and-paste.jpg|90px|left|link=Copy_and_Paste_Data_to_Other_Softwares]]

[[Copy and Paste Data to Other Softwares]]

[[File:Open-a-Chart-Data-File-in-PowerChrom-Software.jpg|90px|left|link=Open_a_Chart_Data_File_in_PowerChrom_Software]]

[[Open a Chart Data File in PowerChrom Software]]

== C4D Conductivity Detector ==

[[File:C4d-procedure-powerchrom.jpg|90px|left|link=A_Procedure_for_C4D_Analysis_in_PowerChrom_Software]]

[[A Procedure for C4D Analysis in PowerChrom Software]]

[[File:C4D Profiler V2 Software to Optimise C4D Settings, thumb.jpg|90px|left|link=C4D Profiler_V2_Software_to_Optimise_C4D_Settings]]

[[C4D Profiler V2 Software to Optimise C4D Settings]]

[[File:C4D Configurator Software thumb.jpg|90px|left|link=Configurator_Software_to_select_C4D_Settings_with_ER815_and_ER825_with Serial_Firmware]]

[[C4D Configurator Software]], to configure C4D Settings in the ER815 and ER825 with Serial Firmware

[[File:Trigger-in-mce.jpg|90px|left|link=HV_Sequencer_to_Trigger_PowerChrom_Software_in_Microchip_Electrophoresis]]

[[HV Sequencer to Trigger PowerChrom Software in Microchip Electrophoresis]]

[[File:Et225b.jpg|90px|left|link=A_Procedure_for_Microchip_Electrophoresis_with_C4D]]

[[A Procedure for Microchip Electrophoresis with C4D with the ET225 and ER455]]

[[File:QuadSequencer software Simulator, High Voltage Sequencer-02.jpg|90px|left|link=Simulator_Mode_in_QuadSequencer_Software]]

[[Simulator Mode in QuadSequencer Software]]

'''Obsolete Videos'''

[[File:C4d profiler in powerchrom,newicon.jpg|90px|left|link=The_C4D_Profiler_in_PowerChrom_Software_to_Optimise_C4D_Settings]]

obsolete video: [[The C4D Profiler in PowerChrom Software to Optimise C4D Settings]]

[[File:C4d-detector-software.jpg|90px|left|link=Using_the_C4D_Detector_Software_to_Control_the_ER125_C4D_Detector]]

for obsolete ER125 product: [[Using the C4D Detector Software to Control the ER125 C4D Detector]]

== SDx Tethered Membranes ==

[[File:Sdx1 thumb.jpg|90px|left|link=How_to_assemble_a_tethaPlate_cartridge]]

[[How to assemble a tethaPlate cartridge]]

[[File:Sdx2 thumb.jpg|90px|left|link=Making_a_tethered_membrane]]

[[Making a tethered membrane]]

== FIA Flow Injection Analysis ==

[[File:Fia extension.jpg|90px|left|link=Integrate_a_Peak_and_Calibration_Curve]]

[[Integrate a Peak and Calibration Curve]]

[[File:Fia print.jpg|90px|left|link=Print_a_Report]]

[[Print a Report]]

== isoPods ==

[[File:Isopods-video-thumb.jpg|90px|left|link=The_isoPods_for_Recording_Temperature,_pH,_Conductivity_and_Dissolved_Oxygen]]

[[The isoPods for Recording Temperature, pH, Conductivity and Dissolved Oxygen]]

[[File:Serial-port-monitor2.jpg|90px|left|link=Serial_Port_Monitor]]

[[Serial Port Monitor]]

== Electrochemical Impedance Spectroscopy (EIS) ==

[[File:Z100-loopback-thumb.jpg|90px|left|link=Z100_Loopback_Test]]

[[Z100 Loopback Test]]

[[File:Z100-blank-test-thumb3.jpg|90px|left|link=Z100_Blank_Test]]

[[Z100 Blank Test]]

[[File:ZMAN basics.jpg|90px|left|link=ZMAN_Basic_Overview_of_ZMAN_software]]

[[ZMAN Basic Overview of ZMAN software]]

[[File:ZMAN1 open.jpg|90px|left|link=ZMAN1_Open_a_Data_File]]

[[ZMAN1 Open a Data File]]

[[File:ZMAN2 preview.jpg|90px|left|link=ZMAN2_Preview_and_Edit_Data]]

[[ZMAN2 Preview and Edit Data]]

[[File:ZMAN3 Kramers.jpg|90px|left|link=ZMAN3_Kramers-Kronig_Consistency]]

[[ZMAN3 Kramers-Kronig Consistency]]

[[File:ZMAN4 modeling.jpg|90px|left|link=ZMAN4_Modeling]]

[[ZMAN4 Modeling]]

[[File:ZMAN5 auto.jpg|90px|left|link=ZMAN5_Automatic_Model_Search]]

[[ZMAN5 Automatic Model Search]]

[[File:ZMAN6 circular.jpg|90px|left|link=ZMAN6_Circular_Fitting]]

[[ZMAN6 Circular Fitting]]

Connecting the C4D to the Beckman Coulter CE

2019-10-10T03:20:31Z

Oliver: /* Equipment Required */

[[File:IMG 1229.JPG|300px|thumb|right|Figure 1. eDAQ C4D with Beckman Coulter PA 800plus]]
[[File:DSC03945.jpg|300px|thumb|right|Figure 2. C4D headstage connected to the capillary]]
[[File:Analog output channels on BC CE instrument.jpg|300px|thumb|right|Figure 3. Analog output channels on CE instrument.]]
[[File:Figure 4. External Detector Adapter from Beckman Coulter.jpg|300px|thumb|Figure 4. External Detector Adapter from Beckman Coulter]]
[[File:Figure 5. Connections of the capillary with the screws and gaskets.jpg|300px|thumb|Figure 5. Connections of the capillary with the screws and gaskets]]
[[File:Figure 6. Trigger signal on left side of CE instrument.jpg|300px|thumb|Figure 6. Trigger signal on left side of CE instrument]]

''This application note describes how to connect the eDAQ C4D system to the P/ACE MDQ and PA 800 plus capillary electrophoresis instruments from Beckman Coulter.''

== Introduction ==
The eDAQ C4D can be connected to the Beckman Coulter CE instruments, providing contactless conductivity detection for the instrument.
Both the C4D headstage and UV detector can be connected to the capillary at the same time, enabling both types of detection to be performed with a single sample injection.

== Equipment Required ==
* C4D hardware unit, either:
** [Http://www.edaq.com/ER225 ER225 C4D Data System] to record both C4D and UV signals in the eDAQ software.
** [http://www.edaq.com/ER815 ER815 C4D Detector] to record both C4D and UV signals in Beckman Coulter software (may require an external A/D interface if the CE doesn't have an analog input),
** [http://www.edaq.com/ER815 ER815R C4D Detector] to record only the C4D signal in [http://www.edaq.com/ES280 PowerChrom], or
** [https://www.edaq.com/ER825 ER825R Two Channel C4D Detector] to record both C4D and UV signals in PowerChrom or Beckman Coulter software
* [http://www.edaq.com/ET120 ET120 C4D Headstage for Capillary Electrophoresis]
* Beckman Coulter CE instrument
* Two sets of the External Detector Adapter (EDA) part number 144822, which can be purchased from Beckman Coulter.
* Signal cable:
** For ER225: [http://www.edaq.com/EC008 EC008 BNC to alligator clips cable] (with alligator clips removed), or
** For ER815: [http://www.edaq.com/EC001-4 BNC to BNC Cable]
* Trigger cable:
** For ER225: use a simple tinned end to tinned end double-wire cable, or
** For ER815: EC073 Trigger cable
* [https://www.edaq.com/EC020 EC020 Standard Test Solutions for C4D Applications]

== Choice of Software ==
The data from both the eDAQ C4D and Beckman Coulter UV/LIF/PDA detectors can be displayed in real time, using either the eDAQ software or the Beckman Coulter PA 800 plus Software. Use the [Http://www.edaq.com/ET120 ET120 C4D Headstage] and select either the:
* [http://www.edaq.com/ER815 ER815 C4D Detector] can be configured by the user to use either [http://www.edaq.com/ES280 PowerChrom] or third-party software like Beckman Coulter software. The analog output from the C4D may be connected to the CE, so the PA 800 plus Software records data from both detectors. This may require an external A/D interface if the CE doesn't have an analog input. The delta K signal from the C4D Detector should be connected to the A/D interface input. The A/D interface is then connected to the computer using a serial connection. The [https://www.edaq.com/ER825 ER825R model] includes PowerChrom software and can record the signal from both C4D and UV detectors.
* [https://www.edaq.com/ER825 ER825R Two Channel C4D Detector], can also be configured by the user to use either [http://www.edaq.com/ES280 PowerChrom] or third-party software like Beckman Coulter software. The ER825R model includes PowerChrom software and can record the signal from both C4D and UV/LIF/PDA detectors.
* [Http://www.edaq.com/ER225 ER225 C4D Data System] to use the eDAQ software. The analog output from the UV/LIF/PDA detector (on the CE) may be connected to the eDAQ system, so the eDAQ software records data from both detectors.

== Analog Outputs on the CE ==
There are three BNC analog outputs located on the left side panel of the CE instrument, as shown in Figure 3. The outputs are 1000 mV full scale deflection. For PA 800 plus firmware version 1.5 or higher, the output is programmable from the control software. In version 1.2, 1000 mV is equal to 1 absorbance unit (AU) with a fixed 10% negative offset. The high voltage output is the uncontrolled parameter, current or voltage, of the high voltage power supply. In this instance, 1000 mV is equal to 30,000 V or 300 µA in all firmware versions.

== External Detector Adapter ==
The Beckman Coulter CE instrument uses a liquid to cool the capillary. The eDAQ [http://www.edaq.com/ET120 ET120 C4D Headstage] can be connected to the capillary using two sets of the External Detector Adapter (EDA) part number 144822, which can be purchased from Beckman Coulter. Each EDA kit includes:

* 144734 loop reservoir
* 144895 red screw
* 144818 red double end conical gasket
* 144834 which includes:
** 970298 (x4) black O-ring
** 966233 (x4) blue conical gasket
** 144809 (x4) blue screw
** 144832 tubing

The assembled EDA is shown in Figure 4. The continuous capillary has been labelled as three parts. Part 3 should be as short as possible.

The length of Part 1 should be the same length as the overall length of the capillary when the UV detector is used. This allows for the same separation length. The liquid loop should be as short as possible to save on cooling liquid and space in the cartridge. The tubing may be bent while immersing in hot water and then placed in cold water to preserve the shape.

The C4D cable may exit the cartridge and instrument though grooves provided.

The connections of the capillary with the screws and gaskets is shown in Figure 5.

Ensure that you position the C4D headstage near the end of the capillary that is grounded, away from the end of the capillary where the high voltage is applied. This is to ensure that the high voltage doesn’t arc from the background electrolyte inside the capillary, through the thin wall of the capillary, to the headstage and on to the C4D hardware, which could damage the equipment.

== Triggering Start of Recording ==
The trigger signal (found on the left side of the CE instrument) may be used to trigger the eDAQ software to start recording. Using a cable, connect pin 9 (CE instrument) to the TRIG + (C4D hardware unit) and pin 10 to TRIG —, as shown in Figure 6.
Setting up of software:
* PA 800 plus Software: make a Method, go to Instrument Setup, then in Time program, enter Time = 0 and Event = Relay 2 On.
* eDAQ PowerChrom software: In the Inject Settings window, select "Wait for Inject". Or in eDAQ Chart software: In the menu Setup, Trigger, choose External Trigger to start data recording.

== Citations ==
* The eDAQ C4D was used with the P/ACE MDQ instrument (Beckman Coulter) for the simultaneous determination of kanamycin, its related substances and sulphate in kanamycin sulphate. Kanamycin is an aminoglycoside antibiotic that lacks a strong UV-absorbing chromophore, so direct UV detection cannot be used. The limit of detection (LOD) and limit of quantitation (LOQ) for kanamycin were 0.7 and 2.3mg/L, respectively. [http://dx.doi.org/10.1002/jssc.201100267 DOI: 10.1002/jssc.201100267]
* The quantification of amikacin in bronchial epithelial lining fluid in neonates was performed using the Beckman Coulter P/ACE MDQ and the eDAQ C4D. [http://dx.doi.org/10.1128/AAC.00277-11 DOI: 10.1128/AAC.00277-11]
* The P/ACE MDQ was used with the eDAQ C4D, collecting the C4D data in the Beckman Coulter 32 Karat software, for the analysis of amikacin and its related substances. Amikacin is a semisynthetic aminoglycoside antibiotic that lacks a strong UV absorbing chromophore or fluorophore. The LOD and LOQ were 0.5 mg/L and 1.7 mg/L, respectively. The method yielded an effective improvement in simplicity and analysis time (6 minutes). This is important for routine application compared to the method obtained using UV detection after derivatization (35 minutes), and to the liquid chromatography method (75 minutes). [http://dx.doi.org/10.1002/elps.201100688 DOI: 10.1002/elps.201100688]
* El-Attug et al used the eDAQ C4D and Beckman Coulter CE for the detection of tobramycin and its related substances. The LOD and LOQ are 0.4 and 1.3 mg/L respectively. It was noted that contactless conductivity detection is useful for the analysis and assay of aminoglycosides such as tobramycin, and that it can be a good alternative to derivatization in case of non UV-absorbing substances. [http://dx.doi.org/10.1016/j.jpba.2011.09.032 DOI:10.1016/j.jpba.2011.09.032]

Frequently Asked Questions Electrodes

2019-09-04T01:26:38Z

Oliver:

Frequently Asked Questions Electrodes

2019-09-04T01:25:43Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]
* DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
* REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

Download the pdf Instruction Sheet from: [[File:ET069 ET072 Instruction Sheet.pdf]]

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== ET073 Use in Organic Solvents ===

'''Question:''' I want to use the eDAQ [https://www.edaq.com/ET073-1 ET073] Refillable Miniature Ag/AgCl Reference Electrode in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last inquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of Hydroflex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the [https://www.edaq.com/ET070 Hydroflex reference electrode] hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of Hydroflex in the daily lab routine certainly is the application as RHE. You simply dip Hydroflex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As Hydroflex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

ANSWER

Usually when the user exchanges the hydrogen source (cartridge) in time - that means before the hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of, for example, 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

CLEANING

Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.

STORAGE

Always clean the microelectrode before storing:
* Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
* Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999% for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T08:53:40Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

Download the pdf Instruction Sheet from: [[File:ET069 ET072 Instruction Sheet.pdf]]

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== ET073 Use in Organic Solvents ===

'''Question:''' I want to use the eDAQ [https://www.edaq.com/ET073-1 ET073] Refillable Miniature Ag/AgCl Reference Electrode in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last inquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of Hydroflex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the [https://www.edaq.com/ET070 Hydroflex reference electrode] hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of Hydroflex in the daily lab routine certainly is the application as RHE. You simply dip Hydroflex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As Hydroflex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

ANSWER

Usually when the user exchanges the hydrogen source (cartridge) in time - that means before the hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of, for example, 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

CLEANING

Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.

STORAGE

Always clean the microelectrode before storing:
* Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
* Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999% for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

File:ET069 ET072 Instruction Sheet.pdf

2019-09-02T08:51:14Z

Oliver:

Frequently Asked Questions Electrodes

2019-09-02T08:48:43Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== ET073 Use in Organic Solvents ===

'''Question:''' I want to use the eDAQ [https://www.edaq.com/ET073-1 ET073] Refillable Miniature Ag/AgCl Reference Electrode in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last inquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of Hydroflex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the [https://www.edaq.com/ET070 Hydroflex reference electrode] hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of Hydroflex in the daily lab routine certainly is the application as RHE. You simply dip Hydroflex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As Hydroflex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

ANSWER

Usually when the user exchanges the hydrogen source (cartridge) in time - that means before the hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of, for example, 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

CLEANING

Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.

STORAGE

Always clean the microelectrode before storing:
* Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
* Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999% for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T08:41:52Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== ET073 Use in Organic Solvents ===

'''Question:''' I want to use the eDAQ [https://www.edaq.com/ET073-1 ET073] Refillable Miniature Ag/AgCl Reference Electrode in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last inquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of Hydroflex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the [https://www.edaq.com/ET070 Hydroflex reference electrode] hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of Hydroflex in the daily lab routine certainly is the application as RHE. You simply dip Hydroflex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As Hydroflex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T08:35:48Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== ET073 Use in Organic Solvents ===

'''Question:''' I want to use the eDAQ [https://www.edaq.com/ET073-1 ET073] Refillable Miniature Ag/AgCl Reference Electrode in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T08:34:22Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== ET073 Use in Organic Solvents ===

'''Question:''' I want to use the eDAQ [https://www.edaq.com/ET073-1 ET073] Refillable Miniature Ag/AgCl Reference Electrode in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T08:32:26Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

= Other Electrodes =

=== Use in Organic Solvents ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T08:27:13Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 '''Electrodes showing drift'''
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water.

== Storage ==

=== Long term storage ===

ANSWER

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use in Organic Solvents ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T08:22:55Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes [https://www.edaq.com/ET069-1 ET069] and [https://www.edaq.com/ET072-1 ET072]: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage ==

=== Long term storage ===

ANSWER

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use in Organic Solvents ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T06:03:59Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes ET069 and ET072: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage ==

=== Long term storage ===

ANSWER

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use in Organic Solvents ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T06:00:29Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes ET069 and ET072: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage ==

=== Long term storage ===

ANSWER

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:59:50Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on Use ===

Leakless electrodes ET069 and ET072: DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== General Questions ===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage ==

=== Long term storage ===

ANSWER

Leakless electrodes ET069 and ET072 can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes should last for many months if not several years. Because eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use ET072 and ET069 electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use in aggressive solvents ===

QUESTION

Can the ET072 and ET069 leakless electrodes be used in organic solvents, perchlorate and silver salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:54:30Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on the use of Leakless electrodes ET069 and ET072 ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:52:21Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General ==

=== General Notes on the use of Leakless electrodes ET069 and ET072 ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Use and Solvents ==

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:51:45Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General Questions ==

=== General Notes on the use of Leakless electrodes ET069 and ET072 ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage Questions ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

== Questions on Use and Solvents ==

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:50:49Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

== General Questions ==

=== General Notes on the use of Leakless electrodes ET069 and ET072 ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

== Storage Questions ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

== Questions on Use and Solvents ==

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:47:44Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== General Notes on the use of Leakless electrodes ET069 and ET072 ? ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:47:17Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

= ET069 and ET072 Leakless Ag/AgCl Reference Electrodes =

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== General Notes on the use of Leakless electrodes ET069 and ET072 ? ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

= Other Electrodes =

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:45:45Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

== ET069 and ET072 Leakless Ag/AgCl Reference Electrodes ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== General Notes on the use of Leakless electrodes ET069 and ET072 ? ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

== Other Electrodes ==

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:42:58Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

== ET069 and ET072 Leakless Ag/AgCl Reference Electrodes ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

=== General Notes on the use of Leakless electrodes ET069 and ET072 ? ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

== Other Electrodes ==

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:42:04Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

== ET069 and ET072 Leakless Ag/AgCl Reference Electrodes ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

=== General Notes on the use of Leakless electrodes ET069 and ET072 ? ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

== Other Electrodes ==

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:41:13Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

== ET069 and ET072 Leakless Ag/AgCl Reference Electrodes ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

=== General Notes on the use of Leakless electrodes ET069 and ET072 ? ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

== Other Electrodes ==

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Frequently Asked Questions Electrodes

2019-09-02T05:40:06Z

Oliver:

''You can learn more about the electrodes by looking at [https://www.edaq.com/electrodes-transducers-accessories our range of electrodes], the relevant [https://www.edaq.com/research-applications research sections], and for voltammetric electrodes: the [https://www.edaq.com/wiki/Setting_up_the_EChem_Startup_System videos], and [https://www.edaq.com/wiki/Application_Notes#Electrochemistry application notes].''
__TOC__

== ET069 and ET072 Leakless Ag/AgCl Reference Electrodes ==

=== Long term storage of Leakless electrodes ET069 and ET072 ? ===

ANSWER

Leakless electrodes can be stored for both short and long term duration's in 0.05 to 0.1 M sulfuric acid. Based on this storage method the electrodes shouls last for many months if not several years. Beacuse eDAQ has no control over the use of these electrodes our warranty is limited to 3 months from date of invoice.

=== General Notes on the use of Leakless electrodes ET069 and ET072 ? ===

DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR PIN.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE by gripping the electrode by its PEEK body and carefully removing the plastic cap.

The electrode utilizes a unique junction which is robust and highly conductive but not porous. There is no glass used in the construction.

The electrode cannot be reﬁlled.

The electrode is not affected by hydroﬂuoric acid and common dilute acids, and bases. It is resistant to most commonly used organic solvents. If the electrode is left to dry for a very long period of time, it should be immersed in deiniozed water for a few hours before use.

Read instructions regarding Long Term storage of electrodes.

If using the electrode in solutions containing ions that form precipitates with chloride and/or potassium ions, then DO NOT store the electrode in potassium chloride solution.

If using the electrode in dry organic solvent, the electrode should be rinsed with acteone (to remove water), then rinsed with the ﬁnal solvent. The electrode should be stored in 0.05-0.1 M sulfuric acid, NOT the organic solvent when not in use.

Depending on the choice of solvent, substrate molecules, and level of care, the electrode should last many months if not several years.

An old electrode suffering from potential drift can sometimes be reactivated by subjecting it to a large oxidizing potential (+4 V) in a two electrode system (use a wire for the counter electrode) in a KCl solution for 10 –15 seconds then waiting 30 seconds for stabilization.
Material adsorbed on the electrode surface can be removed by careful polishing on ﬁne sand paper (or with abrasive powder). Alternatively, try immersing in strong acid (e.g. 6 mol/L H2SO4) for 30 minutes then sonicate, and repeat if necessary.

== Other Electrodes ==

=== When do Electrodes require cleaning? ===

See the application note [[Cleaning and Polishing Voltammetric Electrodes]]

ANSWER

1. If they look dirty they probably are and cleaning should be done.

2. If the electrochemistry reaction produces any sort of insoluble material (including any sort of electrodeposition or electropolymerization reaction) then cleaning of the working electrode (and maybe also the auxiliary electrode) will be required.

3. If you get strange peaks in a cyclic voltammogram run when the the electrodes are placed in fresh solvent/electrolyte then (assuming the electrolyte solution is pure) then the working electrode surface should be cleaned.

4. If the current is unexpectedly small then the working (or auxiliary) electrode surface may be coated with a non conductive material. Although by this stage it would normally be visibly fouled.

5. If you get the expected voltammetric peaks but at wrong E values then the reference electrode may be exhausted and need regenerating or replacement.

6. If you get oscillations/noise in starting a volumetric experiment then the reference electrode may be clogged or broken giving an open circuit. If this is suspected then repeat the experiment without the reference electrode attached. If you get a similar result then the reference electrode needs cleaning or replacement.

Our [https://www.edaq.com/ET030 ET030 Electrode Polishing Kit] is useful for cleaning electrodes.

=== Effect of high pH values on ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

A customer would like to know if the [https://www.edaq.com/ET072-1 ET072] Leakless Miniature Ag/AgCl Reference Electrode is stable in extreme pH-conditions. It would be used for several weeks in pH 12-13 environments. Would that be a problem you think ?

ANSWER

The LF electrodes were kept in 5 M potassium hydroxide for few days and in 3 M in sodium hydroxide for over a year. No junction damage occurred. A little shift in potential might occur, but the electrode functions well

=== ET072 Leakless Miniature Ag/AgCl Reference Electrode Extreme operating conditions ===

QUESTION

A customer would like to know if the ET072 Leakless Miniature Ag/AgCl Reference Electrode will endure 1M
KOH solution @ 80°C conditions ?

ANSWER

ET072 was boiled in KOH for 15 min then left it to cool down for one hour in KOH. There were no apparent change in conductivity or potential.

Soaked one ET072 in 5 M KOH at room temperature for weeks. There was no damage.

This is an important advantage, since researchers use toxic mercury/mercury oxide electrodes with porous junctions because normal Ag/AgCl electrodes are not stable due to the formation of Ag(OH) which is converted to Ag2O. So our ET072 electrode can be used in extreme acid or extreme base. These electrodes have been soaked for long periods >300days and even boiled in 100g/l Sulfuric acid without damage.

=== Measuring Sugars using Zensor Electrodes ===

QUESTION

Customer asked about measuring total carbohydrates (Sugars in sweet beverages)

ANSWER

Copper-plated Zensor electrodes have been used to detect various sugars (which is the type of carbohydrates I guess your customers are interested in). See the Zen2005 paper "An electrochemical cell coupled with disposable screen-printed electrodes for use in flow injection analysis". Copper plating of carbon Zensor electrode (eg [https://www.edaq.com/ET083-40 ET083]) is also described in this paper. These electrodes can be used with the [https://www.edaq.com/ET066 Zensor Flow cell] or the customer might be able to build their own flow cell.

Since then Zensor also produce a 'copper nanoparticle' electrode that is suited for sugar detection, see their 'NCSE' series screen printed working electrodes, (brochure enclosed, in traditional Chinese [[File:Ncse.pdf]]). We don't stock the electrodes but when we last enquired about them they sold in a pack of 8 for the same price as charged for a pack of 40 of the carbon electrodes (ie five times more expensive than ET083).

=== Instructions in using Leak-Free Electrodes ===

QUESTION

Customer asked for instruction regarding use of ET072 electrodes

ANSWER
ET072 PLEASE DO NOT APPLY TOO MUCH PRESSURE ON THE CONNECTOR.
REMOVE THE CAP PROTECTING THE TIP BEFORE USE.
ET072 was developed with the use of conventional reference electrodes.
ET072 utilizes a unique junction which is robust and highly conductive but not porous.
ET072 junction is resistant to most commonly used organic solvents. It is not affected by hydrofluoric acid and common dilute acids and bases.
Please contact us for further information.
There is no need to store ET072 in concentrated chloride solution.
If the electrode is left to dry for a very long period of time, it should be immersed
in water for a few hours.
If using the electrode in solutions containing ions that form precipitates with chloride and potassium ions, we DO NOT recommend storing the electrode in potassium chloride solution.
If using the electrode in dry organic solvent, the electrode should be washed with
solvent or acetone to remove water.
The electrode should be stored in aqueous solution NOT the organic solvent.

=== High resistance of ET072 Leakless Miniature Ag/AgCl Reference Electrode ===

QUESTION

I recently purchased a miniature leakless Ag/AgCl reference electrode from eDAQ, and I am trying to use it for cyclic voltammetry in a rotating disk electrode setup. I am getting very bizarre results and my potentiostat is having trouble giving me a quality uncompensated resistance value for the cell (gives high phase error). I did not have this problem when working with an Ag/AgCl with a porous junction. Is the resistance of these leakless electrodes necessarily higher than that of those with porous frits? Is there a difference in experimental applications between your miniature leakless electrodes and regular-sized ones (i.e., is there a range of suitable currents for the smaller electrode vs. the larger one)?

ANSWER

The ET072 has an internal resistance (impedance) of less than 10 kohm. In most cases this will not present a problem for the potentiostat however in some cases large electrode impedance (depending on factors such as choice of electrolyte solution, distances between working, reference, and auxiliary electrodes, etc) may cause potentiostat instability, especially if positive feedback iR compensation is being used.

In such cases it may be necessary to:

1. run the potentiostat in 'high stability' mode (refer to the potentiostat manual)

2. select a different reference electrode with lower impedance. The 'leakier' the electrode the less resistance/impedance it will have.

3. change the electrochemical cell design and especially bring the electrodes closer together,

4. increase the concentration of the background electrolyte, or

5. introduce a capacitor of appropriate size between the reference and auxiliary electrode.

=== O-Rings used by eDAQ ===

QUESTION

What is the O-ring material used by eDAQ on various electrodes.

ANSWER

Nitrile/NBR a synthetic rubber used in many critical applications.
https://en.wikipedia.org/wiki/Nitrile_rubber

=== Calomel Electrodes ===

QUESTION

Does eDAQ sell Calomel electrodes?
For information on calomel electrodes check out our web page at

https://www.edaq.com/wiki/Reference_Electrode_Potentials#The_Calomel_.28Hg.2FHg2Cl2.29_Electrode

ANSWER

No we don't. Because of the many restrictions on selling and shipping mercury containing products (calomel is a mixture of mercury and mercurous chloride) we refer our customers to one of these sellers.

Commercial calomel electrodes are available from:

Koslow Scientific (USA) http://www.koslow.com
ALS Co. Ltd (Japan) https://www.als-japan.com/1390.html
Ionode Pty Ltd (Australia) http://www.ionode.com

The real question is why anyone would want to use a calomel electrode in the first place? If the answer is that they have always done (they were once considered easy to make by the user) then the obvious question is why can't they use a silver/silver chloride electrode.

There may be some technical reason that precludes the use of a silver/silver chloride electrode, and this may need to be verified. But otherwise why not use an off-the-shelf silver/silver chloride electrode, including our leakless reference electrodes - they are usually cheaper and come in a greater variety of shapes and sizes.

=== Use of ET072 and ET069 in Ionic Liquids ===

QUESTION

Can ET069 and ET072 leakless ref electrodes be used in ionic liquids (RTILs Room Temperature Ionic Liquids)?

ANSWER

These electrodes should be OK to use in most ionic liquids. However the potentials under these conditions are not established standards and it would be best at the end of the experiment to use a cyclic voltammogram of ferrocene in the ionic liquid to determine reportable values.
Ferrocene is also often used as a reference for volumetric experiments in organic solvents.

=== Use of ET072 and ET069 in aqueous solutions of Bases and Acids ===

QUESTION

Is it possible to use these electrodes in diluted HCLO4 (aqueous solution at ~2M) during several hours?
Is it possible to use it in diluted HF solutions (aqueous solution up to 5M) ? - within which pH range (aqueous solution) can it be used?

ANSWER

The electrode material is not affected by the acids mentioned above. This was established years ago. The electrodes can handle 5M acid or 5M base. There might be a small shift in potential which is reversible but no physical damage or leakage occurs. Can be used over the full range of pH and temperatures

See other relevant questions and answers.

=== Use of ET072 and ET069 in aggressive solvents ===

QUESTION

Can the above leakless electrodes be used in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids?

ANSWER

Our leakless electrodes ET072 and ET069 enable you to
perform your experiments in organic solvents, perchlorate and silver
salts solutions, or Hydrofluoric acids without being worried about
clogging or degradation!
It can also be used for long term experiments without the worry that
the filling electrolyte be diluted or run out.
This leakless reference electrode uses our newly developed
conductive junction. The filling electrolyte is
confined to the barrel and will not leak at all (zero leakage). The
junction has very high conductivity with resistance under 10 kohm. It
has exceptional mechanical stability, zero swelling, resistance to
organic solvents, and is robust. The junction potential is independent of
the sample nature or ionic strength. The electrode body is constructed
from PEEK for superior chemical resistance. The filling electrolyte
(3.4 M KCl) does not leak through the junction which prevents sample
contamination with chloride and potassium ions. This means no clogging
and no need for double junction. Since the electrode construction does
not involve any glass, it can be used in hydrofluoric acid solutions.

=== Use of HydroFlex Hydrogen Electrodes ===

QUESTION

We have some laboratory electrochemical test cells that need a good reversible hydrogen reference electrode. The working electrolyte for these cells is 32% caustic soda at 90 degrees C. Will the Hydroflex reference electrode hold up well in these conditions?

ANSWER

Hydroflex is usable as a Reversible, Standard and Normal Hydrogen Reference Electrode (RHE SHE, NHE).

The most common use of HydroFlex in the daily lab routine certainly is the application as RHE. You simply dip HydroFlex into your solution, directly. The advantages are obvious. You don't need a liquid junction, you don't have diffusion potentials and you don't contaminate your solution by ions flowing out of your reference system.
As HydroFlex needs no maintenance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.

Hydroflex is particularly suitable as a reference electrode in aqueous acid or alkali solutions, and can be used at pressures up to 10 bar and temperatures of up to 210 °C. pH range -2 to pH 16

QUESTION

What cleaning is recommended for the Hydroflex Hydrogen Reference Electrode?

Usually when the user exchanges the Hydrogen source (Cartridge) in time - that means before the Hydrogen gas has been exhausted - the reference electrode will not require cleaning.

In the case that the user missed that moment (for example exchanging the cartridge after 8 month instead of the adjusted lifetime of for example 6 month) then the user should perform a more complete cleaning as mentioned in the manual. The complete cleaning should be done, as aggressive solutions may attack the metals (Pt, Pd) when no Hydrogen is available.

1. Clean the catalyst with HNO3 for some 3-4 minutes.
2. Wash out any residuals with water.
3. Dry the whole electrode in order to get rid of water inside of Hydroflex.

When following this procedure the Hydroflex is usually restored to a "new" condition and should work properly.

=== Conductivity Probes ET901 ET902 ET903 Lose the Black Plating ===

[[File:ET903 Conductivity Probe loses its black plating.png|300px|thumb|right|ET903 Conductivity Probe loses its black plating]]

QUESTION

Please see the photo of ET903 electrode. When we first delivered the electrode to our user, the red marked platinum plate was plated by some black substance. But now the black substance peels off from the platinum plate.

Please advise us whether we can use the electrode continuously or not.

ANSWER

These electrodes or probes use platinum which is platinised. See this [https://en.wikipedia.org/wiki/Platinum_black#Process_of_platinization_of_platinum_metal Wikipedia explanation]

After platinization, the electrode should be rinsed and stored in distilled water. The electrode loses its catalytic properties on prolonged exposure to air and becomes more likely to damage.

If some of the platinum black has been removed, the K value will change, but can be adjusted for by calibration. If most has been removed, it will require to be re-platinised.

Platinum black on the surface of the electrode is fragile and can be shaken off or damaged and may need recoating. These electrodes are suitable for continuous use in a stable environment. The length of continuous use may depend on the exact conditions of flow/ temperature and mechanical conditions.

The above is relevant for the [https://www.edaq.com/ET901 ET901], [https://www.edaq.com/ET902 ET902] and [https://www.edaq.com/ET903 ET903] conductivity probes.

'''Instructions for replatinization of electrode surfaces using a YSI 3139 PLATINIZING KIT'''

The kit consists of a 4.5 VDC supply containing three “D” (flashlight) cells, a
milliammeter, a current control, and a polarity reversal switch. A 3 ½ oz. Jar is included
for use as a platinizing solution container.
Platinizing solution is not included with the kit. It is available in 2 oz. quantities –
enough to platinize at least 25 cells – as YSI No. 3140. This solution consists of 1.77
gm Platinic Chloride and .015 gm Lead Acetate dissolved in 2 oz. distilled water.

'''OPERATION'''

1. Place the solution container in the clip provided on the instrument.
2. Pour 2 oz. platinizing solution into the container.
3. Place the cell in the solution and connect the cell leads to the binding posts.
4. Adjust the current control for 50 MA indication on the meter, tap meter.
5. Platinize for 3 to 4 minutes. Reverse the polarity ever 30 seconds.
6. Rinse the cell in running water for about 15 minutes.
7. Rinse the cell in distilled water.

'''CELL CLEANING'''

It may be necessary to clean the cell in order to ensure a good coating of
platinum black. Since the electrodes in the YSI 3400 Series Cell are soldered with fine
gold, DO NOT CLEAN THIS CELL IN AQUA REGIA OR IN SOLUTIONS WHICH MIGHT ATTACK GOLD.

The conductivity cell should be cleaned as follows:

1. Prepare a solution containing 100 ml isopropyl alcohol, 50 ml concentrated HCl, and
50 ML distilled water.
2. Immerse the cell electrode chamber in the solution for 3 to 4 minutes.
3. Rinse the cell in distilled water.

=== Leakless Reference Electrodes general questions===

> 1. what is the resistance of the leakless ref electrode ?

less than 10 kohm

> 2. is there a difference between the miniature and the larger LF electrodes (aside from the size) ?

No.

> 3. is there any experience with use of these LF electrodes used over months or even years (drift of potential due to ions intruding from the electrolyte?)

Depending on conditions (solvents, temperature, etc) and frequency of use you can usually expect months to years of use.

> 4. what is the pin material ?

gold plated

> 5 what is the maximum operating temperature.

The electrode will operate at temperatures below 90 Centigrade. Exceeding this temperature can cause boiling of the internal solution leading potentially to electrode damage.

> 6 Electrodes showing drift
Customer reported drift of 50mV after a week of use in a fixed 7.5pH environment.
ANSWER: The electrode can handle extreme cases of acid and bases. However there might be some material aadsorbed on the electrode surface. Please dip in 0.5-1M sulfuric acid and/or 1M hydroxide for a few minutes and then acetone or ethanol for additional cleaning.
If the electrode has been left dry for some time, soak for a few hours in water. Read other questions regarding the ET072.

> 7 '''Storing Leakless electrodes'''
It is recommended to store the electrodes in 0.05 -1M sulfuric acid, NOT just distilled waterwith some KCL.

Please remember these electrodes are designed primarily for ease of use, and generally need to be replaced when they begin to show excessive drift. See information sheet at

https://www.edaq.com/product_sheets/transducers/ET072_Leakless_Miniature_Ag-AgCl_Reference_Electrode.pdf. for Maintenance details.

=== ET073 Reference Electrode in Organic solvent ===

'''Question:''' I want to use your refillable Ag/AgCl reference electrode (ET073) in water-free conditions. Therefore, I filled it with AgNO3 (0.1M) in ACN. However, the potential of this Ag/AgNO3 reference electrode is not constant. Should I remove the darker AgCl coating from the silver wire?

'''Answer provided by Dr Paul Duckworth''':Customer is attempting to make a silver/silver ion electrode for use in organic solvents (in the case 'AN' acetonitrile).

To do this the AgCl coating on the silver wire MUST be completely removed. This can be done by using abrasive paper to rub the AgCl coating off. You can also use 1 mol/L ammonia solution to dissolve the AgCl.

You can then fill the ET073 electrode with 0.1 mol/L silver salt solution (usually silver nitrate, tetrafluroborate, or hexafluorophosphate).

You should now get a steady potential (but you need to keep temperature constant, to at least within 1 centigrade degree, to keep the potential constant to within 1 mV).

Note that this type of reference electrode must not be used in a solution that contains ions like Cl-, Br-, I-, SCN-, OH-, S2-, or any other ion that will react with Ag+ ion to form a precipitate.

=== ET1120 Oxygen electrode Cleaning and storage ===

• CLEANING
Using any electrode in solutions containing protein requires the electrode be rinsed with an enzyme cleaning solution.
After each use, we recommend cleaning our electrodes with Terg-a-zyme (Alconox, Inc.) or a chromic/sulfuric acid glass cleaning solution by submerging the electrodes for a couple of minutes in order to remove all protein from the glass and reference junction.
This will prolong the useful life of the electrodes.
STORAGE
Always clean the microelectrode before storing:
• Long-term (over 2 weeks): Return the probe to its original container and prepare it in the same condition in which you received it. Usually this means simply moistening the sponge located in the bottom of the protective glass tube with pH 4 buffer.
• Short-term: The probe can be left in an acid pH buffer solution (pH 4.01).

=== ET05x ET07x Electrodes Metal purity ===

All metals used in the construction of ET05x and ET07x electrodes have a purity level of 99.99%. The next step is 99.999 for ultra pure metals - there is no need to go further than 99.99% for electrodes.

As an example for copper:

Alloy 101 OFE Copper is the highest purity grade of copper at 99.99%. OFE stands for oxygen-free electrolytic and replaces the acronym OFHC. It has been electrolytically refined in a carefully regulated, oxygen-free environment to reduce the level of oxygen to .001% or below.

Measuring the Conductivity of Melt Water from Arctic Ice Cores

2019-08-15T03:06:09Z

Oliver: /* Some of the Equipment Required */

[[File:Ice core from NEEM.jpg|300px|thumb|right|Figure 1. Ice core from NEEM (North Greenland Eemian Ice Drilling)]]

''The eDAQ C4D was used to measure the very low conductivity of water melted from ice cores taken from the South Dome in Greenland.''

== Introduction ==
Ice cores enclose a variety climate proxies that are valuable for understanding the past climate of our planet. These proxies include trace gases, salts, dust, stable isotopes and acids. Continuous Flow Analysis (CFA) is a method of measuring these chemical impurities by analyzing the water that derives from melting a certain piece cut from the ice core. The [http://www.edaq.com/c4d-contactless-conductivity-detector eDAQ C4D] was used to measure the conductivity of shallow ice cores taken from the South Dome in Greenland.
The results are compared with a bench top conductivity meter and with other detection methods of the CFA system as well.

This original research was conducted in 2014 by Maria Arvaniti, Anders Svensson and Paul Vallelonga from the Centre for Ice and Climate at the Niels Bohr Institute, University of Copenhagen, Denmark:

[http://www.iceandclimate.nbi.ku.dk/publications/theses/M._Arvaniti_Thesis.pdf “Application of Contactless Conductivity Detection to Ice Core Analysis”] (2.5 MB pdf, Master’s thesis 2014)

== Experimental ==
[[File:Schematic overview of the Continuous Flow Analysis system2.jpg|400px|thumb|right|Figure 2. Schematic overview of the Continuous Flow Analysis system]]

The performance of the C4D was tested for discrete measurements of conductivity using standards with a range of conductivity values typically found in ice cores. Various experimental parameters were then investigated and optimised, such as tubing material, tubing inner diameter, C4D frequency and detector response time.

The C4D was then used to measure the conductivity of water melted from an ice core. Figure 2 shows the Continuous Flow Analysis system. The ice core is placed vertically inside the melting unit over a heated melt head. This produces a steady stream of the melted ice core water. This is passed through a dedubbler to remove ancient air trapped in the ice. The water stream is then split and passed through the different detectors:
* Contactless conductivity detector (C4D)
* Benchtop conductivity meter
* Dust particle detector
* Absorption spectroscopy detector
* Fluorescence detector

The absorption and fluorescence detectors are used for detecting the various chemical species incorporated inside the water sample. For example, calcium was detected using the fluorescence detector, while sodium and hydrogen cations were detected using the absorption detector. Conductivity and dust measurements are non-destructive methods used for measuring the bulk conductivity of ions and the dust content in the sample, respectively.

== Some of the Equipment Required ==
* [Http://www.edaq.com/ER225 ER225 C4D Data System]
* [http://www.edaq.com/ET131 ET131 Configurable C4D Detector/Monitor Headstage]; the conductivity of the water from Arctic ice cores is very low, so a modified version of the ET131 was developed to measure conductivity in the range of 100 nS/cm to 20 µS/cm. We now also have a 20 nS/cm to 4 µS/cm version.
* Amber Science Model 3082 Multi-Function Conductivity Meter with 829 Conductivity Micro Flow Cell.
* Tubing: clear perfluoroalkoxy alkane (PFA) tubing with 0.03 inch inner diameter and 0.0625 inch (1/16 inch) outer diameter; tubing with various inner diameters and materials (PEEK and PFA) were tested.

[[File:Optimum c4d frequency.jpg|250px|thumb|right|Figure 3. Good linearity between conductivity and C4D output voltage at 19.2 kHz frequency]]
C4D Settings:
* Amplitude = 100% (20 Vpp (Voltage peak-to-peak)).
* Frequency = 19.2 kHz, see Figure 3.

== Optimizing the Experimental Procedure ==
Various experiments were carried out to optimize parameters in the setup.
* Tubing inner diameter; tubing with inner diameters of 0.02, 0.03 and 0.04 inches were tested. As expected, the C4D produced a larger signal when using tubing with a larger inner diameter. The larger ID also reduced the back pressure. Tubing with 0.03 inch ID was chosen.
* Tubing material; tubing made from perfluoroalkoxy alkane (PFA) and polyether ether ketone (PEEK) were tested. perfluoroalkoxy alkane tubing was chosen.
* C4D signal response with different frequencies; different C4D frequencies were tested. The frequency of 19.2 kHz was chosen as it showed good linearity between C4D output voltage and conductivity, see Figure 3. The [http://www.edaq.com/chart-extensions Multipoint calibration] feature in the eDAQ [http://www.edaq.com/ES500 Chart software] may be used to calibrate such a signal.
* Detector response time; Response time is the time required for an instrument to respond to a sudden step change of the input. It is defined as the time required for the signal of the step function to rise from 5% to 95% of the final output. The C4D showed a faster response in conductivity changes than the benchtop conductivity meter.

== Results ==
[[File:C4d signal vs year.jpg|600px|thumb|right|Figure 4. Conductivity profile between 1960 and 2010]]

Figure 4 shows the conductivity profile for the South Dome ice core between 1960 and 2010. The black lines indicate peaks in both the conductivity and hydrogen cations concentration (not shown).

The conductivity of the South Dome ice core has two outstanding peaks between the years 1980-1990. They are 4-5 times larger than the mean conductivity range of the majority of data, and they match the hydrogen cation peaks recorded for the same years. Volcanic eruptions emit large amounts of gases and aerosols into the atmosphere, especially in the form of sulphuric acid and carbon dioxide. These large amounts of impurities injected into the atmosphere are deposited onto the surface of the ice, producing a higher conductivity signal. It is possible that the two peaks between 1980-1990 are volcanic signals, however, comparison with sulphate detection methods is recommended for further confirmation.

[[File:Ice core results at depth 4-11m.jpg|600px|thumb|right|Figure 5. Results from 2003 (10.5m) to 2009 (4.3m)]]

Figure 5 shows results for the ice core from 4-11m depth, which corresponds to the year 2003 (10.5m depth) to 2009 (4.3m depth).

The blue curve is calcium, the violet is sodium, the purple is dust, the green is hydrogen cations, the orange is conductivity measured by the benchtop conductivity meter, and the red is conductivity measured by the C4D detector. The measurements from the eDAQ C4D and the benchtop conductivity meter showed a linear relation with high correlation. The eDAQ C4D exhibits a faster response in conductivity changes than the benchtop conductivity meter.

Troubleshooting Issues with the Potentiostat

2019-08-13T09:01:49Z

Oliver:

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the blue and green LEDs lit, with the green LED occasionally flashing orange/yellow. The O’load LED should have turned off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the [https://www.edaq.com/wiki/Check_the_Performance_of_the_Potentiostat_with_Potentiostat_Maintenance_Check Potentiostat Maintenance Check], where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage divided by the resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry. See Fig 1.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished and it asks to save the file, type in the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen to start the run.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
#* A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
#* A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

=== Please send me an email: ===
# Explain which LED lights are lit on the front of the potentiostat (or e-corder if using a modular potentiostat) when the EChem software is on.
# If red LED lights are flashing, tell me sequence of 5 short or long flashes (for example: long, long, short, short, long).
# Do the two cyclic voltammetry runs, one using a one megaohm resistor and one using the potentiostat’s dummy cell.
# Use the Page comment function in the software to indicate which run is the one megaohm resistor and which is the dummy cell.
# Attach the EChem software data file to an email and send it to me. I need to be able to see the data file rather than a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:46:58Z

Oliver: /* Potentiostat Maintenance Check with the Dummy Cell */

Troubleshooting Issues with the Potentiostat

2019-08-13T08:44:07Z

Oliver: /* Confirming the Potentiostat Turns On and Communicates with the Software Properly */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the blue and green LEDs lit, with the green LED occasionally flashing orange/yellow. The O’load LED should have turned off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the [https://www.edaq.com/wiki/Check_the_Performance_of_the_Potentiostat_with_Potentiostat_Maintenance_Check Potentiostat Maintenance Check], where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage divided by the resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry. See Fig 1.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished and it asks to save the file, type in the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
#* A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
#* A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:42:53Z

Oliver: /* Confirming the Potentiostat Turns On and Communicates with the Software Properly */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the blue and green LEDs lit, with the green LED occasionally flashing orange/yellow. The O’load LED should have turned off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the [https://www.edaq.com/wiki/Check_the_Performance_of_the_Potentiostat_with_Potentiostat_Maintenance_Check Potentiostat Maintenance Check], where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry. See Fig 1.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished and it asks to save the file, type in the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
#* A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
#* A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:36:13Z

Oliver: /* Confirming the Potentiostat Turns On and Communicates with the Software Properly */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the blue and green LEDs lit, with the green LED occasionally flashing orange/yellow. The O’load LED should have turned off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry. See Fig 1.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished and it asks to save the file, type in the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
#* A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
#* A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:32:12Z

Oliver: /* Potentiostat Maintenance Check with a Resistor */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the green LED flashing green and orange/yellow, and the O’load LED should turn off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry. See Fig 1.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished and it asks to save the file, type in the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
#* A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
#* A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:31:20Z

Oliver:

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the green LED flashing green and orange/yellow, and the O’load LED should turn off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry. See Fig 1.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished, give it the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
#* A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
#* A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:30:27Z

Oliver: /* Potentiostat Maintenance Check with the Dummy Cell */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the green LED flashing green and orange/yellow, and the O’load LED should turn off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished, give it the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
=== Potentiostat Maintenance Check with the Dummy Cell ===
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
#* A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
#* A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:29:46Z

Oliver: /* Potentiostat Maintenance Check with the Dummy Cell */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the green LED flashing green and orange/yellow, and the O’load LED should turn off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished, give it the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
[[File:CV of dummy cell on ER467.jpg|400px|thumb|right|Fig 2. CV of dummy cell on ER467]]
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
# A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
# A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA (see Fig 2).
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

File:CV of dummy cell on ER467.jpg

2019-08-13T08:27:33Z

Oliver:

Troubleshooting Issues with the Potentiostat

2019-08-13T08:21:35Z

Oliver: /* Potentiostat Maintenance Check with a Resistor */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the green LED flashing green and orange/yellow, and the O’load LED should turn off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|400px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished, give it the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
# A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
# A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

Troubleshooting Issues with the Potentiostat

2019-08-13T08:21:15Z

Oliver: /* Potentiostat Maintenance Check with a Resistor */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the green LED flashing green and orange/yellow, and the O’load LED should turn off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
[[File:EChem CV settings for PMC.jpg|300px|thumb|right|EChem software settings]]
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished, give it the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
# A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
# A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.

File:EChem CV settings for PMC.jpg

2019-08-13T08:19:36Z

Oliver:

Troubleshooting Issues with the Potentiostat

2019-08-13T08:18:31Z

Oliver: /* Confirming the Potentiostat Turns On and Communicates with the Software Properly */

=== Confirming the Potentiostat Turns On and Communicates with the Software Properly ===
* Connect the power cable, USB cable and electrode cable to the potentiostat. If you are using a modular potentiostat and e-corder, connect them together as explained in the [https://www.edaq.com/edaq-product-manuals potentiostat manual].
* Turn the potentiostat on and observe the LED lights on the font of the potentiostat (if you are using a modular potentiostat and e-corder, look at the lights at the front of the e-corder)
* After a few seconds, you should see a blue and green LEDs lit, and also the O’load (overload) lit. If you see this, the potentiostat is turning on properly. See the [https://www.edaq.com/edaq-product-manuals potentiostat or e-corder manual] to learn more about the LED lights.
* If you see a red LED, this indicates a problem. Try to turn the potentiostat off, wait a few seconds, then turn back on again, to see if you can see the correct LED lights. If you still see red LEDs lit, make a note of the sequence of 5 short or long flashes (for example: long, long, short, short, long) and then email the sequence to the eDAQ engineer.
* Launch EChem software on the computer and observe the LED lights. You should see the green LED flashing green and orange/yellow, and the O’load LED should turn off. If you see this, the EChem software is communicating with the potentiostat properly.

If both the potentiostat and software have started properly, the next step is to test if the potentiostat is working properly. This is done using the Potentiostat Maintenance Check, where a known voltage is applied across a known resistor, and the measured current is compared against the theoretical current, using [https://en.wikipedia.org/wiki/Ohm%27s_law Ohm’s Law]: current = voltage / resistance.

=== Potentiostat Maintenance Check with a Resistor ===
# Find a one megaohm resistor (from any good electrical shop).
# Connect the potentiostat’s electrode cable to the resistor, with the green clip (working) on one side of the resistor, and both the yellow clip (reference) and red clip (counter, or auxiliary) on the other side of the resistor.
# In the EChem software, go to the menu Technique, and select Cyclic Voltammetry.
#* In Limits, set Upper to 1000 mV and Lower to -1000 mV.
#* In Ramp, set Initial to -1000 mV, set Rate to 200 mV/s, set Width to 10 mS, set Height to 2 mV.
#* Set Number of Cycles to 1, set Samp. Period to 5 ms, set Rest Time to 2 s.
#* Deposition and Clean Time should not be clicked.
# Click ok.
# Set the current Range, on the right side of the screen (under i Channel) to 20 µA.
# Click Start in the bottom right of the screen.
# You should see a diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA.
# When the scan is finished, give it the name “Potentiostat Maintenance Check”.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “one megaohm resistor”.

=== Potentiostat Maintenance Check with the Dummy Cell ===
# Click “Potentiostat”, under the current Range, to open the potentiostat window.
# In Cell, click Dummy (to select the dummy cell)
# Click ok.
# Click Dummy Cell in the bottom right of the screen.
# Depending on which eDAQ potentiostat you have (as they have different resistance values for their dummy cell), you should see either:
# A diagonal line, starting at -1 V and -1 µA, going to +1 V and +1 µA, or
# A diagonal line, starting at -1 V and -10 µA, going to +1 V and +10 µA.
# Click the small page comment symbol, in the bottom left of the screen, and in the page comment window, type “dummy cell”.

Save the file with both runs, one using the resistor and one using the dummy cell, close EChem software and attach the EChem data file to an email and send it to your eDAQ engineer. We need to be able to see the data file rather than just a screen capture of the data.