Differential Pulse Voltammetric Determination of Paracetamol Using Activated Glassy Carbon Electrode

Abstract

The electrochemical property of paracetamol was investigated at a glassy carbon electrode and activated glassy carbon electrode. Differential pulse voltammetry and cyclic voltammetry were used as diagnostic techniques in the determination of paracetamol. The activated glassy carbon electrode exhibited excellent electro-catalytic behaviour for the oxidation of PAR as evidenced by the enhancement of the oxidation peak current and the shift in the oxidation peak potential to less positive values by (13mv) in comparison with a bare GCE. In the present work the activated glassy carbon electrode was prepared by activating 200 s in a time base technique at a potential of 1750 mV. The electrode process of paracetamol was studied and some the experimental parameters which affect the response paracetamol, such as pH, effect of PAR concentration and scan rate on AGC electrode. The analysis of cyclic voltammogram gave fundamental electrochemical parameters including the electroactive surface coverage, the electron transfer coefficient and the heterogeneous rate constant (k s). The variation of scan rate study shows that the system undergoes adsorption controlled process. The equation of the calibration curve was found to be: I p =0.429C + 6.43, R 2 =0.993. The LOD and LOQ for the developed method were determined to be 8×10-8 mol L-1 and 2.6×10-7 mol L-1 respectively. Phosphate buffer pH 7.0 was selected for analytical purpose.