DETERMINATION OF SEVERAL CATECHOLS ON BARE AND POLYMER COATED GLASSY-CARBON ELECTRODE

Glassy carbon electrodes were coated with a copolymer of styrene and maleic acid anhydride. The voltammetric behavior of catechol, ascorbic acid, dopamine, and DOPAC was examined at both bare and coated electrode using cyclic voltammetry and modified differential pulse voltammetry. Electrochemical pretreatment increased peak current of catechol and its derivatives; the polymer coating caused significant decrease of peak currents and shift of peak potentials. The signal of ascorbic acid is greatly suppressed, while that of DOPAC disappears even after polymer coating.