The determination of lead,copper and cadmium by anodic stripping voltammetry at a mercury thin-film electrode

The determination of lead, copper and cadmium by anodic stripping voltammetry at a wax-impregnated graphite electrode, pre-plated with mercury, has been investigated. Electrode preparation and cell design are discussed, and the effects of mercury loading and sample pH on electrode sensitivity are described. Detection limits and precision on aqueous samples are reported. Calibration graphs are linear for lead and cadmium, but non-linear for low concentrations of copper. The depression of peak current and shift of peak potential for copper in chloride media are described and an explanation is proposed. Precision and recovery of metal additions are reported for digested samples of whole blood.