title: Simultaneous quantification of major cannabinoids and metabolites in human urine and plasma by HPLC-MS/MS and enzyme-alkaline hydrolysis.
abstract: A high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) method for simultaneous quantification of Δ9-tetrahydrocannabinol (THC), its two metabolites 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), and four additional cannabinoids (cannabidiol (CBD), cannabigerol (CBG), tetrahydrocannabivarin (THCV), and cannabinol (CBN)) in 1 mL of human urine and plasma was developed and validated. The hydrolysis process was studied to ensure complete hydrolysis of glucuronide conjugates and the extraction of a total amount of analytes. Initially, urine and plasma blank samples were spiked with THC-COOH-glucuronide and THC-glucuronide, and four different pretreatment methods were compared: hydrolysis-free method, enzymatic hydrolysis with Escherichia Coli β-glucuronidase, alkaline hydrolysis with 10 M NaOH, and enzyme-alkaline tandem hydrolysis. The last approach assured the maximum efficiencies (close to 100%) for both urine and plasma matrices. Regarding the figures of merit, the limits of detection were below 1 ng/mL for all analytes, the accuracy ranged from 84% to 115%, and both within-day and between-day precision were lower than 12%. Finally, the method was successfully applied to real urine and plasma samples from cannabis users. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Basque Country, Spain.
authors.forename: Oier
authors.initials: O
authors.lastname: Aizpurua-Olaizola
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Basque Country, Spain.
authors.forename: Iratxe
authors.initials: I
authors.lastname: Zarandona
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Basque Country, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Ortiz
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Basque Country, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Navarro
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Basque Country, Spain.
authors.forename: Nestor
authors.initials: N
authors.lastname: Etxebarria
authors.affiliation: Analytical Chemistry Department, University of the Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Basque Country, Spain.
authors.forename: Aresatz
authors.initials: A
authors.lastname: Usobiaga
mesh_terms: D002186:Cannabinoids / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D013759:Dronabinol / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D006801:Humans; D057230:Limit of Detection; D011619:Psychotropic Drugs / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D052616:Solid Phase Extraction / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D002186:Cannabinoids; D011619:Psychotropic Drugs; D013759:Dronabinol
keywords: cannabinoids and metabolites; enzymatic-alkaline glucuronide hydrolysis; high performance liquid chromatography-mass spectrometry; plasma and urine analysis; solid-phase extraction