STUDIES ON THE VOLTAMMETRIC BEHAVIOR OF A BISMUTHIOL I-CONTAINING CARBON-PASTE ELECTRODE - DETERMINATION OF TRACES OF BISMUTH

The voltammetric behavior of a bismuthiol I-containing carbon paste el ectrode was studied. Bismuthiol I is electroactive, when mixed with ca rbon paste as an electrode modifier, and is oxidized at 0.3 V and re-r educed at -0.6 V (vs. SCE). Nevertheless, it can be used as a modifier of carbon paste electrodes for the preconcentration and subsequent vo ltammetric measurement of bismuth, if suitable measurement conditions for the analysis are met. Bismuth(III) can be preconcentrated from aci dic solutions onto this electrode under open circuit conditions. Linea rity between current response and concentration can be achieved for 0. 005 to 4 mug/ml bismuth using cathodic differential pulse voltammetry after preconcentration for 0.5 or 2 minutes. The interferences as well as various parameters for the preconcentration and measurement of bis muth(III) were investigated.