Square wave anodic stripping voltammetric determination of Pb2+ using acetylene black paste electrode based on the inducing adsorption ability of I−

Herein, a sensitive and simplified electrochemical method was proposed for the determination of trace levels of Pb2+ by anodic stripping voltammetry (ASV) based on the inducing adsorption ability of I− toward Pb2+. In the presence of low concentration of I−, Pb2+ was induced to accumulate onto the acetylene black (AB) paste electrode surface, and then reduced at −0.90 V. During the following square wave sweep from −0.90 to −0.30 V, the reduced Pb was oxidized, resulting in a sensitive and well-shaped stripping peak at −0.56 V. Further studies indicate that low concentration of I− significantly enhances the sensitivity of determination of Pb2+. After all the experimental parameters were optimized, a novel and sensitive method was developed for the electrochemical determination of Pb2+. The linear range is found to be from 2.0 × 10−8 to 4.0 × 10−6 mol L−1, and the lowest detectable concentration is estimated to be 6.0 × 10−9 mol L−1. This newly proposed method was finally demonstrated with water samples. Otherwise, the anodic stripping responses of Pb2+ on AB paste electrode and graphite paste electrode were compared.