Quantitative Determination of Pentazocine Enantiomers in Human Serum Using Derivatized β-Cyclodextrin-modified Capillary Electrophoresis and Solid Phase Extraction

Abstract

A high performance capillary electrophoresis (HPCE) assay for the quantitation of (-) and (+) pentazocine in human serum was developed. Resolution of the pentazocine enantiomers was achieved using 15mM methyl-β-cyclodextrin (Me-β-CD) in 100mM phosphate buffer pH 2.5. A 72cm uncoated fused-silica capillary at a constant voltage of 20kV was used for the analysis and 0.03mM hexadecyltrimethylammonium bromide (HTAB) was added to the buffer to decrease the adsorption of endogeneous substances onto the silica wall. The analytes of interest were extracted from serum using a solid phase extraction(SPE) procedure. The phenyl SPE cartridge gave good recoveries in excess of 90% for both (-) and (+) pentazocine, without any interferences.