COMPARISON OF BORON-DOPED DIAMOND AND GLASSY CARBON ELECTRODES FOR DETERMINATION OF TERBINAFINE IN PHARMACEUTICALS USING DIFFERENTIAL PULSE AND SQUARE WAVE VOLTAMMETRY

This paper examines the electrochemical oxidation of terbinafine with the boron doped diamond and glassy carbon electrodes. The studies were performed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square-wave voltammetry (SWV). The supporting electrolytes, solution pH, the range of potentials, and the scan rates were optimized. Terbinafine was irreversibly oxidized in all electrolytes, yielding well-defined peaks in the positive potential range. The peak potential shifted towards less positive values as the solution pH increased. Voltammetric determination of terbinafine was performed under the optimized conditions. Using the boron doped diamond electrode, a linear relationship between current and concentration was obtained between 5.44 x 10(-7) and 5.18 and 10(-6) mol/L with SWV and between 7.75 . 10(-7) and 8.55 . 10(-6) mol/L by DPV. At the glassy carbon electrode, a linear relationship between 7.75 . 10(-7) and 8.55 . 10(-6) mol/L was obtained by SWV and between 7.75 . 10(-7) and 1.05. 10(-5) mol/L by DPV. The sensitivity, precision, and selectivity of the procedures were evaluated. In order to check the practical application of the developed methods, the concentration of terbinafine was determined in pharmaceutical preparations.