A novel air assisted alkanol based supramolecular solvent microextraction (AA-ASSME) combined with high-performance liquid chromatography (HPLC) was used for rapid and simple determination of gemfibrozil in plasma samples. Gemfibrozil, 5-(2,5 dimethylphenoxy)-2,2-dimethylpentanoic acid, is a benzene derivative of valeric acid belonging to a drug group known as fibrates [1]. It is clinically effective in reducing serum cholesterol and triglyceride levels. It has also been demonstrated that this drug lowers the incidence of coronary heart disease in humans [2]. Various experimental parameters affecting the extraction efficiencies were optimized by response surface methodology through central composite design (CCD). The optimized extraction condition were undecanol=102 mg, pH=5.0, THF volume=3.0 mL and extraction time=5 cycles. Under the optimum condition, extraction recovery of 80% with relative standard deviation less than10% were obtained for 5 replicated measurments which are satisfactorily consistent with predicted results. The proposed method was successfully applied for preconcentration of the drug in plasma sample with the enrichment factor of 70.
