Study of the potential sweeps in the manual staircase voltammetry

Abstract

Voltammetry can be developed using manual potentiostats. This study focuses on the potential sweeps and its influence on the voltammograms in the manual staircase voltammetry. Oxidations of potassium ferrocyanide, potassium iodide, ascorbic acid and succinic acid were used for the study. Five voltammograms were generated for each analyte. A mathematical approximation of the scans to a linear sweep was used for the quantitative description. The scan rate was the slope of the linear regression. The sweeps were compared to evaluate their repeatability. The influence of the repeatability of the sweeps was checked comparing the limiting currents of the voltammograms for each analyte. The results showed that the manual staircase potential sweeps are generated at random, with a high tendency to be non-repeatable. The scan rates were in correspondence with the common values reported. Although not repeatable manual voltage scans were used, the voltammograms did not show statistical differences.