Simultaneous Differential Pulse Voltammetric Determination of Dopamine and Ascorbic Acid with Antimony Film Modified Electrode

An antimony film modified glassy carbon electrode prepared by electrochemical reduction was used to study its electrochemical properties toward dopamine (DA) and ascorbic acid (AA).It was found that the oxidation potentials of DA and AA at the Sb-film modified GCE were 0.676 V and 0.360 V respectively,with a potential difference of 316 mV,which is much larger than that (136 mV) at the bare GCE.Thus,it was possible to determined DA and AA simultaneously using the Sb-film modified GCE.Linearity range for determination of DA was found in the range of 6.80×10-7-1.33×10-2mol·L-1,and that for determination of AA was found in the range of 2.60×10-6-1.20×10-3mol·L-1.Detection limits found for the analytes were 1.50×10-7,6.70×10-7mol·L-1 respectively.The proposed method has been applied to the analysis of samples of DA injections and of samples of AA tablets,giving results in conformity with the labelled values and giving values of recovery in the range of 97.9%-99.3%.