title: Monitoring of chronic Cannabis abuse: an LC-MS/MS method for hair analysis.
abstract: An advanced analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS), has been developed for the identification and determination in hair of Δ(9)-tetrahydrocannabinol together with its major metabolite 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol. Since the latter is formed endogenously, it allows the assessment of chronic use excluding passive exposure to Cannabis. The sample pre-treatment procedure is based on a feasible incubative extraction followed by a liquid-liquid extraction step. Chromatographic separation was performed using a reversed-phase column and gradient elution with a formic acid/acetonitrile/water mobile phase. The limits of quantitation and of detection were 3pg/mg and 1pg/mg, respectively, for both analytes. The method was successfully applied to the analysis of hair samples from Cannabis abusers; the analyte concentrations found ranged from 55 to 100pg/mg for Δ(9)-tetrahydrocannabinol and from 5 to 10pg/mg for 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol. Accuracy studies also gave satisfactory results (recovery>87%), thus confirming the suitability of the assay for chronic consumption monitoring.
authors.affiliation: Laboratory of Pharmaco-Toxicological Analysis, Department of Pharmacy and BioTechnology (FaBiT), Alma Mater Studiorum - University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Mercolini
authors.forename: Roberto
authors.initials: R
authors.lastname: Mandrioli
authors.forename: Michele
authors.initials: M
authors.lastname: Protti
authors.forename: Matteo
authors.initials: M
authors.lastname: Conti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Serpelloni
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Raggi
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D002908:Chronic Disease; D013759:Dronabinol / Q000031:analogs & derivatives / Q000032:analysis; D005240:Feasibility Studies; D006197:Hair / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D002189:Marijuana Abuse / Q000175:diagnosis*; D015813:Substance Abuse Detection / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol