INFLUENCE OF THE REDOX POTENTIAL OF THE MEDIUM ON STRIPPING VOLTAMMETRIC MEASUREMENT RESULTS

It is shown that raising the redox potential of the medium leads to a substantial decrease in the lifetime of a graphite electrode plated, before use, with mercury. Electrochemical reduction of dissolved oxidants by applying pulses of potentials equal to -0.8 and 0 V extends the electrode service life by up to 2 d. No loss of the analyte elements [copper(II), and cadmium(II)] is detected. The lifetime of an electrode plated with mercury in situ was partly dependent on the redox potential of the medium. When the potential is increased, only the sensitivity of the determination of ions in solution, decreases.