Abstract

Purpose:To study the electrochemical behavior and catalysis mechanism for dopamine and ascorbic using an activated roughened glassy carbon electrode, and to develop a sensitive and selective method for the determination of dopamine and ascorbic acid. Methods:The activated roughened glassy carbon electrode was prepared by potential recycling in a 0.2 mol/l aqueous solution of NaOH. The electrochemical behavior and catalysis mechanism was studied by cyclic voltammetry using this electrode. Results:The oxidation peak of dopamine can be separated by about 200 mV from that of ascorbic acid in one buffer solution (pH 5.72) and by 230 mV in another buffer solution (pH 1.98). The relationship between the peak current and concentration of dopamine is linear over the range 0.2−80 μmol/l
in the buffer solution (pH 5.72) containing ascorbic acid at a concentration three orders of magnitude higher than dopamine. The relationship between the peak current and concentration of ascorbic acid is linear over the range 4−1.2 mmol/l in buffer solution (pH 1.98).
The detection limit of dopamine and ascorbic acid was 0.08 and 0.6 μmol/l, respectively. Conclusions:The proposed method has advantages of low cost, simplicity and high sensitivity, and can be applied successfully to the determination of dopamine and ascorbic acid in synthetic samples.


Keywords:  Electrochemical behavior   Activated roughened glassy carbon electrode   Cyclic voltammetry   Dopamine   Ascorbic acid