Voltammetric Behavior and Determination of Isoniazid in Pharmaceuticals by Using Silver Oxyfluoride Modified Silver Electrode

In the present study, silver oxyfluoride modified silver electrode was employed to electrocatalytic oxidation of isoniazid. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry and amperometry techniques. The modified electrode shows a stable and linear response in the concentration range of 3×10−4 to 2.1×10−3 mol L-1 with a correlation coefficient of 0.9953. The overall number of electrons involved in the catalytic oxidation of isoniazid was found 4 electrons. The diffusion coefficient of 3.11×10−5 cm2 s-1 for isoniazid was also estimated using chronoamperometry study. It has been shown that using the silver oxyfluoride modified silver electrode, isoniazid can be determined by amperometry method with limit of detection of 3.85 µmol L–1. The method was successfully applied for analysis of isoniazid in solid pharmaceutical formulations. The results of the analysis suggest that the proposed method has promise for the routine determination of isoniazid in the products examined.