Alizarin violet modified carbon paste electrode for the determination of trace silver(I) by adsorptive voltammetry

A sensitive and selective procedure for the determination of trace silver(I) at alizarin violet modified carbon paste electrode has been developed. Silver(I) was accumulated on the electrode surface via complex formation with modifier in 0.1 mol/L acetate buffer (pH 5.2). After electrochemical reduction of silver(I) had been carried out, the reoxidation wave of silver(0) appeared at 0.05 V (versus SCE) on scanning the potential in the positive direction in 0.1 mol/L H2SO4 + 2.0 × 10−4 mol/L KBr. For a preconcentration time of 3 min, the detection limit is 1.0 × 10−10 mol/L and the linear range is from 3.0 × 10−10 to 1.2 × 10−7 mol/L. Many coexisting metal ions have little or no effect on the determination of silver(I). The proposed method was applied to the determination of silver in waste water and zinc alloy samples with satisfactory results.