Bismuth Film Electrodes for Indirect Determination of Sulfide Ion in Water Samples at Trace Level by Anodic Stripping Voltammetry

In this paper, the analytical applications of bismuth film electrodes (BiEFs) are summarized in recent years. Using BiEFs as working electrode, an indirect determination method for sulfide in water samples by anodic stripping voltammetry (ASV) is established, based on the determination of residual Cd2+ after reacting with S2-. Under the optimal experimental conditions (0.1 mol L-1 pH 4.5 NaAc-HAc, CCd2+ = 3.6 x 10(-6) mol L-1, deposition potential E-d = -1.2 V, and reaction time t(R) = 120 s), the determination of S2- can be achieved in the range of (0.7-5.0) x 10(-6) mol L-1 with a detection limit (DL) of 2.1 x 10(-7) mol L-1 and a relative standard deviation (RSD, n=10) of 3.6% for 1.7 x 10(-6) mol L-1 S2-. Compared with the previously proposed methods, this method can eliminate the interferences such as Br-, SCN-, PO43-, CO32-, NO2-, Al(III) and Fe(II) efficiently. In addition, the proposed method possesses the distinct advantages of cheap instrument and simple manipulation. It has been successfully applied to the determination of S2- in different spiked water matrices (mineral water, lake water, synthetic wastewater and real wastewater) with recoveries ranging from 95 to 106%.