Detection of cocaine in human urine by solid-phase microextraction and capillary gas chromatography with nitrogen-phosphorus detection

Abstract

A method for extraction of cocaine from human urine with solid-phase microextraction (SPME) is presented. A polydimethylsiloxane-coated SPME fiber was immersed directly into a human urine sample containing cocaine and cocapropylene as internal standard (IS) in a vial to allow adsorption of the compounds. The fiber needle was then injected into the port of a capillary gas chromatography (GC) instrument with nitrogen-phosphorus detection. The SPME-GC gave big peaks for cocaine and IS. Recovery of cocaine and IS with use of the SPME-GC were 20 and 30 %, respectively. The detection limit of cocaine was about 6 ng/0.5 ml of urine.