Electrochemical Oxidation of Loop Diuretic Furosemide at Gold Electrode and its Analytical Applications

Electrochemical oxidation of loop diuretic furosemide at gold electrode was investigated by cyclic, linear sweep and differential pulse voltammetric (DPV) techniques. The electrochemical studies were carried out in methanol: water (10:90) in 4.8 pH with 0.04 mol/l Britton-Robinson buffer as supporting electrolyte at 25±0.20 C. The effects of scan rate, concentration, surfactant and temperature were evaluated. The electrochemical process was observed to be adsorption controlled, irreversible and involving two-electron oxidation. Effects of anodic peak potential (Epa), anodic peak current (ipa) and heterogeneous rate constant (k0) have been discussed. A DPV method with good precision and accuracy was developed for the determination of furosemide in pharmaceutical formulations. The linear response was obtained in the range of 6.0 x 10-6 to 8.0 x 10-4 M with detection limit of 4.12 x 10-8 M. The proposed method was successfully applied to the individual tablet dosage form.