Cathodic Stripping Voltammetric Determination of Tellurium(IV) with in situ Plated Bismuth-Film Electrode

Abstract

A very sensitive and reliable method is proposed for the determination of tellurium(IV) [Te(IV)] by Osteryoung square-wave cathodic stripping voltammetry. This method is based on the reduction of Te(IV) with bismuth(III) onto an edge-plane pyrolytic graphite electrode, followed by a cathodic potential scan. The reduced Te gave a well-defined catalytic hydrogen wave at −1200 mV vs. Ag/AgCl. The peak height of the catalytic wave was directly proportional to the initial Te(IV) concentration in the concentration ranges of 0.01–0.10 and 0.1–1.0 µg L−1 with 30 s deposition time. A 3σ detection limit of 1.0 ng L−1 Te(IV) was obtained with the same deposition time. The relative standard deviation was 3% on replicate runs (n = 5) for the determination of 0.1 µg L−1 Te(IV). Analytical results of natural water samples demonstrate that the proposed method is applicable to the determination of traces of Te(IV).