title: On-line SPE LC-MS/MS for the quantification of Δ9-tetrahydrocannabinol (THC) and its two major metabolites in human peripheral blood by liquid chromatography tandem mass spectrometry.
abstract: A universal and robust analytical method for the determination of Δ9-tetrahydrocannabinol (THC) and two of its metabolites Δ9-(11-OH)-tetrahydrocannabinol (11-OH-THC) and 11-nor-Δ9-carboxy-tetrahydrocannabinol (THC-COOH) in human whole blood was developed and validated for use in forensic toxicology. Protein precipitation, integrated solid phase extraction and on-line enrichment followed by high-performance liquid chromatography separation and detection with a triple quadrupole mass spectrometer were combined. The linear ranges used for the three cannabinoids were from 0.5 to 20 ng/mL for THC and 11-OH-THC and from 2.5 to 100 ng/mL for THC-COOH, therefore covering the requirements for forensic use. Correlation coefficients of 0.9980 or better were achieved for all three analytes. No relevant hydrolysis was observed for THC-COOH glucuronide with this procedure--in contrast to our previous GC-MS procedure, which obviously lead to an artificial increase of the THC-COOH concentration due to the hydrolysis of the glucuronide-conjugate occurring at high pH during the phase-transfer catalyzed methylation step.
authors.affiliation: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, 3012 Bern, Switzerland. stefan.koenig@irm.unibe.ch
authors.forename: Stefan
authors.initials: S
authors.lastname: König
authors.forename: Beat
authors.initials: B
authors.lastname: Aebi
authors.forename: Stephan
authors.initials: S
authors.lastname: Lanz
authors.forename: Martina
authors.initials: M
authors.lastname: Gasser
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Weinmann
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013759:Dronabinol / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D013759:Dronabinol