MERCURY(II) ACETATE NAFION MODIFIED ELECTRODE FOR ANODIC-STRIPPING VOLTAMMETRY OF LEAD AND COPPER WITH FLOW-INJECTION ANALYSIS

A new method for the preparation of mercury film electrodes used in anodic stripping voltammetry is introduced. This method is simple, rapid and eliminates the need for a mercury plating step. In this alternative method, Hg2+ (as in mercury(II) acetate) is incorporated into a Nafion perfluorosulfonate formed on top of a glassy carbon electrode. When a negative potential is applied to the electrode, the Hg2+ is reduced to Hg-0 forming a three dimensional mercury film within a Nafion coating. The modified electrode is very stable in flowing solutions and has several advantages over a conventional preplated mercury film. The modified electrode was used to determine Pb2+(0.07-2.8 mu g ml(-1)) and CU2+ (0.5-2.3 mu g ml(-1)) in industrial effluents.