Voltammetric Determination of Cadmium, Copper and Lead Using Glassy carbon Electrode

Abstract

Cyclic voltammetry and linear sweep voltammetry were used to determine cadmium, copper and lead metal ions using glassy carbon electrode. From cyclic measurements, cadmium, copper and lead showed a well single anodic peak at -547, +191.5 and -520 mV respectively. Several parameters affecting the stripping current response were investigated and optimized. Under optimal conditions, the glassy carbon electrode showed a good linear response to Pb 2+ , Cd 2+ and Cu 2+ in the concentration range from 8x10 -6 M to 1x10 -4 M. The detection limits were 2x10 -7 M for Pb 2+ , 9x10 -7 M for Cd 2+ and 1x10 -7 M for Cu 2+ calculated for a single-to- noise ratio of 3 (S/N = 3). The proposed method was successfully applied for determining Pb 2+ , Cd 2+ and Cu 2+ contents in well water samples. I. Introduction Voltammetry refers to a class of electrochemical techniques in which the current at the working electrode is measured as a function of potential waveform applied to the electrode. The potential of this electrode serves as the driving force for the reaction; i.e. it is controlled parameter that causes the chemical species present in the solution to be electrolyzed (reduced or oxidized) at the surface. The reducing or oxidizing strength of the electrode is controlled by the applied potential (1).