Differential pulse anodic stripping voltammetric determination of lead with heparin modified electrode

Abstract

Abstract A novel differential pulse anodic stripping voltammetry for the determination of trace amounts of lead, using a biomacromolecule heparin drop‐coated modified glassy carbon electrode, has been described. Pb 2 ‐ was deposited on the surface of a heparin‐modified electrode at ‐1.0 V (vs. SCE) via forming Pb 2 ‐heparin and subsequent reduction at the electrode. In the following step, Pb‐heparin was oxidized, and voltammograms were recorded by scanning the potential in a positive direction. Conditions were optimized with respect to the pH of the medium, the mass of drop‐coated heparin, accumulation potential and accumulation time. The peak current was proportional to the Pb 2 ‐ concentration in the range of 2.0X 10 − ‐ 9 to 7.0X 10 − ‐ 7 mol/L. The detection limit was 3.0X 10 − ‐ 10 mol/L. The relative standard deviation was 4.83% for 1.0X 10 − ‐ 8 mol/L Pb 2‐ ( n = 10). The developed method has been applied to the determination of Pb 2‐ in water samples with satisfactory results.