The influence of the surfactant in a perfluorinated emulsion on the determination of thallium,lead and cadmium by anodic stripping voltammetry

The effects of the Pluronic F-68 surfactant in the emulsion are described. A study of the two electrode processes in the measuring cycle shows that the deposition stage is not affected provided that the deposition potential is negative enough. The peak potentials for Pb²⁺ and Cd²⁺ are slightly shifted and the stripping currents are seriously decreased when the differential pulse (d.p.) mode is used, but the inhibition is independent of metal ion concentration and deposition time, and the d.p. mode is suitable for quantitative work. The performance of hanging drop and film mercury electrodes is compared.