Mercolini L.,University of Bologna |
Mandrioli R.,University of Bologna |
Protti M.,University of Bologna |
Conti M.,Irst Cancer Institute Of Romagna |
And 2 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2013
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 Δ9-tetrahydrocannabinol together with its major metabolite 11-nor-9-carboxy-Δ9-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 Δ9-tetrahydrocannabinol and from 5 to 10pg/mg for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol. Accuracy studies also gave satisfactory results (recovery>87%), thus confirming the suitability of the assay for chronic consumption monitoring. © 2012 Elsevier B.V.