Application of stripping voltammetry for the determination of mercury

A method for detecting low concentrations of mercury ions with the help of direct current anodic stripping voltammetry (DCASV) is proposed. For this method, gold and gold-plated electrodes are used. To eliminate the influence of interfering organic surfactants, electrochemical method is used for the probe preparation. Less interference by inorganic substances is attained by the introduction of an additional state in the electrolysis at constant potential after pre-electrolysis, by which interfering elements are stripped from the deposit while mercury remains on the electrode. The lowest detection limit obtained was 0.16μg/L using a gold electrode and a graphite electrode impregnated with a mixture of an epoxy resin and polyethylenamine with a gold cover. The latter electrode can be used for fifty analyses without changing the gold covering. The proposed method was used for the analysis of food, sewage, and drinking water.