Boron-doped diamond film electrode as a sensitive and selective electrochemical sensor for the determination of paracetamol

Abstract

A simple, sensitive and selective differential pulse voltammetry method for determination of paracetamol on a bare (unmodified) boron-doped diamond film electrode has been developed. It was found by cyclic voltammetry that paracetamol provided the quasireversible wave with oxidation peak on the forward scan about +0.90 V and smaller reduction peak on the reverse scan at +0.68 V vs. Ag/AgCl. The effect of supporting electrolyte, pH and scan rate on voltammetric response of paracetamol was studied to select the optimum experimental conditions. The optimal conditions for quantification of paracetamol were obtained in acetate buffer solution at pH 5.0. The oxidation peak of paracetamol was chosen for evaluation and showed a systematic increase in peak current with increase of its concentration. Linear response of peak current on the concentration in the range from 2 × 10-7 to 6 × 10-5 mol L-1, good repeatability (RSD of 1.4% for ten successive measurements) and the detection limit of 1.1 × 10-7 mol L-1 were observed without any chemical modifications and electrochemical surface pretreatment of boron-doped diamond film electrode. The effect of possible interferents appeared to be negligible which evidently proved good selectivity. The practical analytical utility of proposed method was successfully demonstrated by determination of paracetamol in human urine samples and in pharmaceutical formulations (tablets) with results in a close statistical agreement to those declared by producer.