Determination of total antimony(III,V) by square-wave anodic stripping voltammetry with in situ plated bismuth-film electrode

A sensitive and reliable method is described for the determination of total Sb(III, V) at traces levels by Osteryoung square-wave anodic stripping voltammery (OSWASV). This method is based on the co-deposition of Sb(III, V) with Bi(III) onto an edge-plane pyrolytic graphite substrate at an accumulation step. OSWASV studies indicated that the co-deposited antimony was oxidised with anodic scans to give an enhanced anodic peak at about 450 mV vs. Ag/AgCl (sat. KCl). The anodic stripping peak current was directly proportional to the total concentration of antimony in the ranges of 0.01-0.10 µg L-1, 0.10-1.0 µg L-1 and 1.0-18.0 µg L-1 with correlation coefficient higher than 0.995 when 2.0 mol L-1 hydrochloric acid was used. The detection limits calculated as S/N = 3 was 5.0 ng L-1 in 2.0 mol L-1 hydrochloric acid at 180 s deposition time. The relative standard deviation was 5% (n = 6) at 0.10 µg L-1 level of antimony. The analytical results demonstrate that the proposed method is applicable to analyses of real water samples.