Square wave anodic stripping voltammetric determination of Pb 2+ using acetylene black paste electrode based on the inducing adsorption ability of I −

Abstract

Herein, a sensitive and simplified electrochemical method was proposed for the determination of trace levels of Pb 2+ by anodic stripping voltammetry (ASV) based on the inducing adsorption ability of I − toward Pb 2+. In the presence of low concentration of I −, Pb 2+ 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 Pb 2+. After all the experimental parameters were optimized, a novel and sensitive method was developed for the electrochemical determination of Pb 2+. 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 Pb 2+ on AB paste electrode and graphite paste electrode were compared.