A VOLTAMMETRIC METHOD FOR THE DETERMINATION OF LEAD(II) AT A POLY(4-VINYLPYRIDINE)/MERCURY FILM ELECTRODE

摘要

A novel voltammetric method was developed for the determination of trace lead(II) in real samples by square-wave anodic stripping voltammetry at a poly(4-vinylpyridine)/mercury film electrode (PVP/MFE). By applying a preconcentration potential of -1.0 V vs Ag/AgCl in 0.025 M sulfuric acid, lead(II) can be converted into the anionic forms. The analytes are then preconcentrated onto the PVP/MFE by the ionic-exchange effect of the PVP. The fairly good solubility of lead in mercury subsequently helps to increase the preconcentration effect. Various factors influencing the determination of lead by the proposed voltammetric method were thoroughly investigated in this study. The main advantages of the methods are good resistance to interferences, easy detection without deoxygenating, and excellent electrode renewal. The analytical utility of the PVP/MPE using the proposed voltammetric method in the determination of lead is demonstrated by application to various water samples.