VOLTAMMETRIC RESOLUTION OF ASCORBIC-ACID AND DOPAMINE AT CONDUCTING POLYMER ELECTRODES

Electrochemical behavior of dopamine and ascorbic acid binary mixture was examined by cyclic voltammetry and the analysis of a each componen t was performed by differential pulse voltammetry. The electrochemical behavior of these molecules on poly-3-methylthiophene, polypyrrole, p olyaniline electrodes were compared. The effects of electrolyte type a nd its pH, and the film thickness on the voltammetric resolution of th ese molecules were systematically examined. At all the modified electr odes both dopamine and ascorbic acid peaks shifted their positions to more negative potentials with increasing pH, difference between the po sitions remaining almost constant. Type of electrolyte seems to have a n effect on ascorbic acid peak only at the poly-3-methylthiophene elec trode. The effect of increasing film thickness was to observe increase d peak heights.