Preconcentration and Electroanalysis of Copper Species at Electrochemically Activated Glassy Carbon Electrodes

Electrochemically activated glassy carbon electrodes were applied to the preconcentration and electroanalysis of metal species. Activated glassy carbon electrodes were obtained by potentiostatic oxidation at +2.0V in 0.5M sulfuric acid. Copper species were readily extracted onto the modified electrode and were determined electrochemically. Voltammetric peak currents showed linear response for copper concentrations in the range between 1 to 20 μM with a large slope of 2.11 A M^-1 and a correlation coefficient of 0.997. The reproducibility of the voltammetric measurements was found to be within 7 % RSD for five replicate measurements on copper concentration of 10 μM. The modified electrodes could be applied for repeated copper determinations without appreciable deterioration in electrode response. Results suggest that the preconcentration of copper species onto activated electrodes involved primarily cation-exchange interactions with the surface graphite oxide film.