Polarographic behavior of gemfibrozil in the presence of dissolved oxygen and its analytical application

The polarographic behavior of gemfibrozil is investigated in 0.2 mol L-1 KH2PO4-Na2HPO4 (pH 5.8 +/- 0.1)-8% ethanol supporting electrolyte in the absence and the presence of dissolved oxygen. The results demonstrate that the polarographic reduction peak at ca. -1.17 V is a catalytic hydrogen wave after deaeration, and the enhanced reduction peak in the presence of dissolved oxygen is the so-called parallel catalytic hydrogen wave. Based on the parallel catalytic hydrogen wave, a novel method has been developed for the determination of gemfibrozil by single sweep polarography. Calibration plot is linear in the range of 1.8 x 10(-7)-2.4 x 10(-6) mol L-1 and detection limit is 9.0 x 10(-8) mol L-1. The proposed method is applied to the direct determination of the gemfibrozil in pharmaceutical preparations. The proposed method is simpler, faster and more sensitive than the known methods for gemfibrozil analyses.