Simultaneous Determination of Paracetamol and Ascorbic Acid Using Activated Glassy Carbon Electrode

Abstract

Square wave voltammetric technique (SWV) was employed for the detection of APAP and AA by using activated glassy carbon electrode (AGCE). The AGCE was prepared by activating for 200 s at a potential of 1.750 V, sensitivity; 100 μA/V in 0.1 mol L-1 phosphate buffer solution at pH 7.0. It was found that AGCE efficiently electro catalyzed the oxidation of APAP and AA than bare GCE. The cyclic voltammetric study showed that AGCE decreased the overpotential of both paracetamol and ascorbic acid and displayed excellent electrochemical catalytic activities toward APAP and AA compared with bare GCE. The scan rate studies showed that the electrochemical behavior of APAP and AA was controlled by surface adsorption process. In the voltammetry technique, both APAP and AA exhibited sensitive oxidation peaks and gave linear characteristic response. The linear range, quantification and detection limits of APAP were found to be 10 to 100 μmol L-1; 0.517 μmol L-1 and 0.155 μmol L-1, respectively. Similarly, the linear range, quantification and detection limits of AA were found to be 0.4 to 0.95 mmol L-1, 6.32 μmol L-1 and 1.89 μmol L-1, respectively. The interfering study showed that uric acid interfered in the determination of APAP. The proposed method applied to the determination of APAP and AA in pharmaceutical samples with better results. The proposed method was applied for APAP and AA determination in commercial drug formulation paracetamol + Vitamin C SANDOZ with a recovery of 101.05% and 95%, respectively. Key word: Glassy carbon electrode; Activated glassy carbon electrode; Ascorbic acid; Paracetamol; Adsorption; Cyclic voltammetry; Square wave voltammetry;