Hollow fiber liquid-phase microextraction combined with high performance liquid chromatography for the determination of trace mitiglinide in biological fluids.

A hollow fiber liquid phase microextraction (HF-LPME) in conjunction with reversed phase HPLC-UV method was developed for the extraction and determination of trace amounts of the antidiabetic drug, mitiglinide (MIT) in biological fluids. The drug was extracted from 10 mL aqueous sample (donor phase (DP)) into an organic phase impregnated in the pores of hollow fiber, followed by the back extraction into a second aqueous solution (acceptor phase (AP)) located in the lumen of the hollow fiber. Parameters influencing the extraction efficiency including the kind of organic solvent, composition of DP and AP, extraction time, stirring rate and salt addition were investigated and optimized. Under the optimized extraction conditions, high enrichment factors (210-fold), good linearity (5-1000 ng mL(-1)) and detection limit lower than 1.38 ng mL(-1) were achieved. Recoveries of spiked samples were in the range (88.3-96.3%) and (92.0-99.3%) for urine and plasma samples, respectively. The percent relative standard deviation (n=9) for the extraction and determination of three concentration levels (100, 400 and 800 ng mL(-1)) of MIT were less than 10.6% and 13.6% for urine and plasma samples, respectively. The developed method is simple, sensitive and has been successfully applied to the analysis of MIT in biological fluids.