SIMULTANEOUS MEASUREMENT OF COCAINE, COCAETHYLENE, THEIR METABOLITES,AND CRACK PYROLYSIS PRODUCTS BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

We developed a sensitive and specific assay for the simultaneous measu rement of cocaine, cocaethylene, six of their metabolites, and anhydro ecgonine methyl ester, a pyrolysis product, in biological fluids. The assay involves solid-phase extraction columns containing a copolymeric bonded phase for isolation of cocaine analytes, derivatization with N ,O-bis(trimethylsilyl)trifluoroacetamide and 10 g/L trimethylchlorosil ane, and measurement with gas chromatography-mass spectrometry operati ng in the selected-ion monitoring mode. Detector responses for analyte s were linear over a concentration range of 3.1-1000 mu g/L. The limit s of detection were similar to 1 mu g/L for cocaine, ecgonine methyl e ster, and benzoylecgonine and 3-6 mu g/L for the remaining analytes. H ydrolysis of cocaine and artifact formation of anhydroecgonine methyl ester during extraction and assay was <1%. Cocaine and its derivatives appear in different proportions in plasma, saliva, and urine accordin g to the biological fluid and time of measurement. Each biological flu id provides unique information on the disposition of cocaine in human subjects.