title: An automated preconcentration-derivatization system for the determination of cocaine and its metabolites in urine and illicit cocaine samples by gas chromatography/mass spectrometry.
abstract: Although gas chromatography/mass spectrometry (GC/MS) is the most powerful technique for analysing cocaine and its hydrolysis products (benzoylecgonine, ecgonine methyl ester and ecgonine) in urine, the sample pretreatment required is rather laborious and involves a large number of steps. This paper reports a continuous method for the separation (based on the retention properties of cocaine and its major metabolites on a reversed phase C18 column), preconcentration (evaporation under nitrogen) and derivatization (collection of the residue in a few microlitres of derivatizing reagent) of cocaine and its metabolites in urine samples for subsequent analysis by GC/MS. Calibration graphs are linear from 5 to 3000 ng/mL; the detection limits are 1 ng/mL (cocaine and ecgonine methyl ester), 20 ng/mL (benzoylecgonine) and 200 ng/mL (ecgonine). The method was applied to illicit cocaine samples and to urine from a drug addict.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Cardenas
authors.forename: M
authors.initials: M
authors.lastname: Gallego
authors.forename: M
authors.initials: M
authors.lastname: Valcarcel
mesh_terms: D001322:Autoanalysis; D003042:Cocaine / Q000031:analogs & derivatives / Q000032:analysis* / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007202:Indicators and Reagents; D009294:Narcotics / Q000032:analysis* / Q000652:urine; D015813:Substance Abuse Detection
chemical_list: D007202:Indicators and Reagents; D009294:Narcotics; C005618:benzoylecgonine; D003042:Cocaine; C034524:ecgonine methyl ester