Evaluation of Carbon Paste Electrodes Modified with Organic Molecules

In this paper, a novel electrochemical sensor was developed by incorporation of organic molecules into the paste carbon electrode. These electrodes were used for the chemical preconcentration of different heavy metals at trace levels. The organic molecules modified carbon paste electrode (MO-CPE) can preconcentrate heavy metals from aqueous solution to the surface of the modified CPE by forming complexes with these ions and greatly increasing the sensitivity of its determination. The experimental data show that some of the MO-CPEs have high sensitivity, adequate selectivity and reproducibility, and a wide operative linear range of concentrations for the determination of heavy metals in water samples. The MO-CPEs have the advantages of simple methods of synthesis and purification and their low solubility in water. Abstract Three organic molecules were used as modifiers of carbon paste electrodes (CPEs) for the analysis of different metals (Pb 2+ , Cd 2+ and Cu 2+ ) by using Square Wave Voltammetry (SWV) technique. The effect of the modified electrodes (MO-CPEs) on the electrochemical behavior has been shown. The MO-CPEs gives the more sensitivity. The detection limits obtained in all analysis approaching 10 -8 mol/L.