Voltammetric determination of selenosulfate ions at a mercury-film electrode

A procedure is proposed for the voltammetric determination of selenium as selenosulfate (SO 3 Se 2− ) ions at a mercury-film electrode (MFE). Selenosulfate ions are determined in the range from 2 × 10 −4 to 1.0 × 10 −3 M without analyte accumulation, using peak current at −0.92 ± 0.02 V and in the range from 1 × 10 −7 to 2 × 10 −4 M after analyte accumulation with the open circuit, using peak current at −1.18 ± 0.03 V as the analytical signal. The mechanisms of SO 3 Se 2− reduction at an MFE under the conditions of direct voltammetry and stripping voltammetry with accumulation are proposed and discussed.