Anodic Stripping Voltametry at Mercury Film Deposited on Ultrasmall Carbon Ring Electrodes

Anodic stripping voltammetry of lead and cadmium without deliberately added electrolytes has been studied at ultrasmall carbon ring electrodes following in situ deposition of mercury. The stripping of lead has been studied in detail to investigate the dependence of stripping peak current on experimental parameters such as potential scan rate, preconcentration duration, deposition potential, concentration of Hg during deposition and concentration of Pb 2. Anodic stripping voltammetry in solutions without deliberately added supporting electrolyte avoids problems associated with impurities introducing when electrolyte is added. These impurities appear to be highly important when Pb 2 analysis is carried out in dilute solutions. In addition, a unique effects is observed when relatively low concentrations of Hg are used for the in situ deposition step. When low Hg concentrations are used, the stripping current does not decrease as rapidly as expected as the concentration of Pb 2 is reduced. Keywords Stripping voltammetry, Ultrasmall carbon ring electrodes.