Mercury-free anodic stripping voltammetry of lead ions using a PVS-doped polyaniline modified glassy carbon electrode

The advent of stripping voltammetry has improved the performance of analytical voltammetry to a considerable extent.1 The enhanced sensitivity and lower detection limits can be achieved in this technique by enrichment of the analyte prior to voltammetric determination. The common enrichment processes include reduction of metal ions through formation of metal films or amalgams, reductive or oxidative formation of sparingly soluble salts with or without reagent addition, and adsorptive accumulation of chelates or complexes onto the electrode surface. The universal working electrodes for stripping analysis are the stationary mercury electrodes, namely the hanging mercury drop electrode (HMDE) and the electrochemically generated mercury film electrode (MFE). In some cases, carbon-based electrodes as well as the noble platinum and gold metals are used when mercury electrodes pose some complications. Recently, there has been a growing interest in the area of chemically modified electrodes for trace metal analysis.2 Prompted by environmental issues, these investigations are also aimed at the development of mercury-free electrodes for electroanalysis in which lead is of significant concern.3 In this communication we report a totally mercury-free voltammetric stripping technique for the analysis of lead ions using a conducting polymer modified electrode.