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 Pb2+ on AB paste electrode and graphite paste electrode were compared.
Li
Gang
G
Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074, PR China.
Ji
Zhiming
Z
Wu
Kangbing
K