Electrocatalytic Separation for Dopamine and Ascorbic Acid Using Poly-Evans Blue Modified Glassy Carbon Electrode and Simultaneous Determination

Abstract

Voltammetric behavior of the Dopamine(DA) and ascorbic acid(AA) at Poly-Evans Blue modified electrode were studied and a novel method for determination of the content of DA and AA is established.In pH 4.5 phosphate buffer solution,the modified electrode shows enhanced sensitivity and excellent electrochemical discrimination to DA and AA.The relationship between oxidation peak current and the concentration of DA or AA is linear in the range of 1.0 10-6 ~3.0×10-5mol/L and 5.0×10-6~1.05×10-4 mol/L,the detection limit has been estimated as 2.5(10-7 mol/L and 3.0 ×10-7 mol/ L,respectively.The oxidable potential difference of DA and AA was about 184 mV at Poly-Evans Blue modified electrode.So it is used to simultaneously determine the DA and AA without any interference.The interference of other components could be efficiently eliminated at the modified electrode,and this method can be used for determination of DA and AA in real sample with satisfactory results.