Electrochemical behavior and polarographic determination of auronofin

Auronofin in a 50% ethanol:water solution yields, on the dropping mercury electrode, a reduction wave whose E1/2 is a function of pH in the 2 less than pH less than 9 range (E1/2 = -0.036-0.054 pH), and acquires a constant value above pH 9 (E1/2 = -0.50 V, versus saturated calomel electrode). The influence of the variables which affect the reduction process of auronofin in tripotassium phosphate medium was studied. The electrochemical process is reversible and diffusion controlled. Coulometry showed that one electron is involved in the reduction of the drug. Analytical methods are proposed for the determination of auronofin at micromolar levels by DC and DP polarography, with relative standard deviations of 3.2 and 2.4%, respectively.