Sono-voltammetry for Determination of Trace Lead(II) and Copper(II) in Drinking Water

The simultaneous determination of trace Pb(II) and Cu(II) in drinking water by sono-differential pulse anodic stripping voltammetry on a gold nanoparticle-modified glassy carbon electrode was reported. The morphology and size of gold nanoparticles were characterized by atomic force microscopy (AFM). The principal mechanism of the sonochemical reactions that can improves the voltammetry signal was discussed. The results indicated that the sensitivity was improved by the sono-voltammetry. In comparison with the traditional different pulse voltammetry, stripping signals were enhanced 10 times for Pb(II) and 8 times for Cu(II), respectively. The good linear range was 10-250 mu g.L-1 for Pb(II), and 5-200 mu g.L-1 for Cu(II) with correlation coefficients of 0.9943 and 0.9985, respectively. High reproducibility for the gold nanoparticle-modified glassy electrode was indicated from the relative standard deviations of 3.5% for Pb at 50 mu g.L-1 level and 2.2% for Cu at 20 mu g.L-1 level (n=9). The limits of determination were 0.3 ng.mL(-1) for Pb and 0.1 ng.mL(-1) for Cu. Finally, this proposed method was successfully applied to the determination of Pb and Cu in drinking water. The great advantages of the proposed method were characterized by the simplicity, reliability and usefulness for application.