Electrochemical Determination of Paracetamol by a Novel Derivative of Formazan Modified Pencil Graphite Electrode

A modified electrode, based on electrodeposition of 5,5´-(oxybis(4,1-phenylene))bis(3-(2-hydroxyphenyl)-1phenylformazan (BF) onto pencil graphite (PG) electrode, was investigated for the determination of paracetamol in this paper. BF was synthesized for the first time in this paper and used for the modification of PG electrode. The electrochemical performance of the modified (BF/PG) electrodes was investigated by differential pulse voltammetry at phosphate buffer solution. Several important parameters controlling the performance of the BF/PG was investigated and optimized. Two linear regions were observed. The first region demonstrates linearity over a concentration range of 0.05-1 μM with a correlation coefficient (R²) of 0.996. The slope of the second linear region was smaller than the first region´s slope with a wide concentration range of 1-100 μM (R² = 0.976). The detection limit of paracetamol is 2.4×10^-9M (S/N = 3). The proposed low cost BF/PG electrode, showed a stable and reproducible response without any influence of interferents commonly existing in pharmaceutical samples.