Anodic Stripping Voltammetry in the Presence of Fumed Silica and Nonionic Surfactants

In this paper we describe the stripping voltammetric method for the determination of metals in the presence of surfactants at the ppm level. The method employs fumed silica for selective adsorption of surfactants directly in the voltammetric cell. In the present work the suppressing effect of the surfactant is studied. The latter depends mainly on the kind of metal and on the parameters of the deposition stage. The fumed silica usually allows for the full restoration of the suppressed signal. In addition, it is possible to enhance the depolarizer signal in solution with silica suspension if high stirring rates are used during the deposition step. The method is validated by analyzing certified reference material and then tested with the natural sample.