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 x 10(-8) to 4.0 x 10(-6) mol L-1, and the lowest detectable concentration is estimated to be 6.0 x 10(-9) mol L-1. This newly proposed method was finally demonstrated with water samples. Otherwise, the anodic stripping responses of Pb 2, on AB paste electrode and graphite paste electrode were compared. (c) 2006 Elsevier B.V. All rights reserved.