A simple and sensitive indirect determination method for sulfide in water samples by anodic stripping voltammetry (ASV) using mercury-film electrode (MFE) has been developed, which is based on the determination of residual cadmium ion after reaction of Cd2+ with S2−. The linear range is adjustable depending on Cd2+ concentration, for example, the determination of S2− can be achieved in the range of 1.5–7.0 × 10−6 mol L−1 by selecting 3.0 × 10−6 mol L−1 Cd2+. The detection limit is 1.3 × 10−8 mol L−1 under optimum conditions, and the relative standard deviation (RSD, n = 10) for 2.0 × 10−6 mol L−1 S2− is 0.7%. Compared with other methods, this method has the following prominent advantages: with low detection limit, easy to operate and less interference. The proposed method has been successfully applied to the determination of S2− in synthetic wastewater, lake water, beverage, spring water and real wastewater samples.
