Potentiometric Stripping Analysis (PSA)

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Here are some instructions for use of the potentiometric stripping analysis (PSA) feature on newer model ER466 Integrated Potentiostat units with Chart software.

When you open the Potentiostat control panel window (see the manual for the ER466 Potentiostat page 23) you will see a newly added "PSA" button (this is not shown the diagram in the manual).

  1. The PSA button accesses a control panel where you set a set a series of potentials and durations that are applied when you click the 'Start' button to begin an experiment.
  2. After these voltage levels have been applied, and while still recording, the potentiostat auxiliary electrode is automatically disconnected (so the current signal falls to zero) while the potential (RE to WE) is monitored. You can set a duration for this monitoring step.

You can repeat the sequence of steps above (1-2) any number of times to get a continuous signal.   When you 'Stop' recording, the potentiostat is re-set.   It may take a bit of trial and error to get the potentials and durations right for your system.

If you want to repeat the PSA cycles quite quickly (milliseconds) and measure the potential near the end of each PSA cycle, this could be done with the Find command so that the final potential at each PSA cycle could be plotted on another channel.

Another application for this PSA feature is to do an experiment called 'potentiometric stripping analysis'. In this experiment the steps within each PSA cycle can actually be quite long (seconds).