A Lead Film Electrode for Adsorptive Stripping Voltammetric Analysis of Ultratrace Tungsten(VI) in Acidic Medium

For the first time an in situ plated lead film electrode was applied to adsorptive stripping voltammetry at relatively strong acidic conditions of, e.g., pH 2. As an example of the application of such electrode a procedure for ultratrace W(VI) determination by adsorptive stripping voltammetry was elaborated. The procedure is based on the preconcentration of the W(VI)-Alizarin Red S complex at an in situ plated lead film electrode held at -0.575 V (vs. Ag/AgCl), followed by a negatively sweeping square wave voltammetric scan. The proposed voltammetric procedure was applied to W(VI) determination in natural water samples.