Insights into the anodic stripping voltammetric behavior of bismuth film electrodes

Abstract

New insights into the attractive stripping voltammetric performance, scope, and limitations of bismuth film electrodes are presented. The results confirm that the stripping performance of the bismuth electrode compares favorably with that of its mercury counterparts. Measurements of trace copper are feasible despite of its positive stripping potential (versus bismuth). Thallium and indium display well-defined peaks over the 20–100 μg/l range following a 2 min deposition. Most metals, with the exception of copper, (e.g. Pb, Cd, Tl, In), form binary alloys with bismuth, and hence, display well-defined and undistorted peaks. Such sharp peaks result in high resolution (of neighboring signals) and permit convenient multi-elemental measurements down to the low μg/l level. The bismuth-coated electrode is shown to be prone to errors caused by the formation of Cu–Zn intermetallic compound, that can be circumvented by the addition of gallium, in a manner analogous to mercury film electrodes. The new insights should facilitate the rationale design and operation of effective ‘non-mercury’ electrodes.