Voltammetry - Instrument

The primary instrument consist of two important components

Figure: Basic instrument for voltammetry

1. Normal three electrode polarograph.

2. Linear scan voltage generator to give different type of signals.

A polarographic cell is made up of a three electrodes dipped in a solution containing the eletroactive species and excess of inert electrolyte usually called supporting electrolyte.

i) Working electrode, usually a microelectrode whose potential is varied linearly with time.

ii) Reference electrode: Normally a standard electrode is used whose potential is constant throughout the experiment (saturated calomel electrode or Ag/AgCl electrode).

iii) Counter electrode that is a coil of platinum wire or a pool of mercury which simply serves to conduct electricity from the signal source through the solution to the microelectrode.

The potentiostat allow imposing the potential scanning between the working and reference electrodes while the current flowing through the circuit is recorded between the working and auxiliary electrodes.

The computer CVA Trace analyzer from Metrohm Ltd. can be used as an integrated instrument with keyboard or a commercially available personal computer interface to measuring system with software can be used:

i) For send the scanning parameters to the potentiostatic analyzer and check its correctness and accuracy,

ii) Handle a current potential outcome data.