Sodium do-decyl benzene sulfate modified carbon paste electrode as an electrochemical sensor for the simultaneous analysis of dopamine, ascorbic acid and uric acid: A voltammetric study

Sodium do-decyl benzene sulfate modified carbon paste electrode (DDBSMCPE) was first employed for the simultaneous determination of dopamine (DA), uric acid (UA), and ascorbic acid (AA). The modified CPE displayed excellent electrochemical catalytic activities. The oxidation over potentials of DA, UA and AA decreases significantly and their oxidation peak currents increases dramatically at DDBSMCPE. Differential pulse voltammetry (DPV) was used for the simultaneous determination of UA, DA and AA in their ternary mixture. The peak separation between UA-DA and DA-AA is 152 mV and 221 mV, respectively, and the detection limit was 0.01 mu M for DA. The proposed method improved sensitivity for the determination of DA by more than one order of magnitude. The present method was applied to the determination of DA in real sample by using standard addition method and the obtained results were satisfactory with a good recovery of 98%. (C) 2012 Elsevier B.V. All rights reserved.