title: Identification and quantitation of cocaine and its metabolites, benzoylecgonine and ecgonine methyl ester, in hair of Bolivian coca chewers by gas chromatography/mass spectrometry.
abstract: Twenty hair samples obtained from Bolivian mine workers who chewed 3-8 g of coca leaves daily for several years were analyzed for cocaine and its main metabolites, benzoylecgonine (BZE) and ecgonine methyl ester (EME). A new method was developed for the detection and quantitation of cocaine and its metabolites, BZE and EME, from hair in a single procedure. The hair samples were washed, cut into 56 segments (2-cm length), pulverized, and incubated with phosphate buffer and the enzyme beta-glucuronidase-arylsulfatase. After solid phase extraction and derivatization with pentafluoropropionic anhydride/pentafluoropropanol, the drugs were identified and measured by gas chromatography/mass spectrometry (GC/MS) using deuterated cocaine, BZE, and EME as internal standards. The method is reproducible (cocaine, CV = 8%; BZE, CV = 14%) and the detection limit for cocaine and BZE was 0.1 ng/mg, for EME 1 ng/mg. In the different hair segments, cocaine was found to be present in concentrations between 1.4 to 50.6 ng/mg, benzoylecgonine from 0.4 to 17.6 ng/mg, and ecgonine methyl ester traces below the calibration curve of approximately 12.9 ng/mg. In 95% of the cases cocaine exceeded BZE and EME in concentration.
authors.affiliation: Institute of Legal Medicine, State University of Saarland, Homburg, Germany.
authors.forename: M R
authors.initials: MR
authors.lastname: Möller
authors.forename: P
authors.initials: P
authors.lastname: Fey
authors.forename: S
authors.initials: S
authors.lastname: Rimbach
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003041:Coca / Q000378:metabolism*; D003042:Cocaine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008409:Mastication; D008875:Middle Aged; D010946:Plants, Medicinal; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods
chemical_list: C005618:benzoylecgonine; D003042:Cocaine; C034524:ecgonine methyl ester