Sensitive voltammetric determination of famotidine in human urine and tablet dosage forms using ultra trace graphite electrode

Abstract

In this study, direct and sensitive determination of famotidine based on its electrochemical oxidation was investigated in spiked human urine and tablet dosage forms. The electrochemical measurements were carried out in various buffer solutions in the pH range of 0.88 to 12.08 at ultra trace graphite electrode (UTGE) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The best results were obtained for the quantitative determination of famotidine by DPV technique in 0.5 mol L-1 H2SO4 solution (pH=0.30). In this strong acid medium, one irreversible anodic peak was observed. The effect of pH and scan rate on the peak current and peak potential were investigated. The diffusion-controlled nature of the peak was established. For optimum conditions described in the experimental section, a linear calibration curve for DPV analysis was constructed in the famotidine concentration range 2 x 10-6 - 9 x 10-5 mol L-1. Limit of detection (LOD) and limit of quantification (LOQ) were 3.73 x 10-7 and 1.24 x 10-6 mol L-1 at UTGE respectively. Repeatability, precision and accuracy of the developed technique were checked by recovery studies in spiked urine and tablet dosage forms.