Trace Determination of Azathioprine by Differential Pulse Polarography

A simple and rapid differential pulse polarographic method was developed for the trace determination of azathioprine. A welldefined polarogram with three peaks was obtained in acetate buffer (pH 5.0) with peak potentials -0.27 V, -0.73 V and -1.02 V. The current-concentration linearity was found extend up to 5 x 10 mol L (r = 0.9992) with minimum detection limit of 2.8x10 mol L. The values of relative mean deviation, standard deviation and coefficient of variation were 4.3%, 1.48 and 1.23% respectively for 1 x 10 mol L of azathioprine indicating high degree of precision. Marketed formulations of azathioprine were analyzed by calibration curve and standard addition methods. Recovery experiments were found to be quantitative, and analysis to determine the mass per tablet was obtained within ±0.2% of the expected value. The studies have shown that the method is simple, reproducible and accurate and can be used in the analysis of marketed formulations.