title: Development and validation of a liquid chromatography tandem mass spectrometry method for the determination of cannabinoids and phase I and II metabolites in meconium.
abstract: A liquid chromatography-tandem mass spectrometry (LC-MSMS) method was developed and fully validated for the determination of Δ9-tetrahydrocannabinol (THC), 11-hydroxyTHC (OHTHC), 11-nor-9-carboxyTHC (THCCOOH), 8-β-11-dihydroxyTHC (diOHTHC), cannabinol, cannabidiol, and THC and THCCOOH glucuronides in 0.25±0.02g meconium. Samples were homogenized in methanol and subjected to cation exchange solid-phase extraction. Chromatographic separation was performed on a Kinetex C18 column (50 mm×2.1mm, 2.6μm) at 35°C, with a gradient of 0.1% formic acid in water and acetonitrile at a flow rate of 0.3 mL/min; total run time was 10min. Two transitions per analyte were monitored in MRM mode. The method was specific and sensitive; LOD was from 1 to 2ng/g, and LOQ from 4 to 10ng/g; linearity ranged from 4 to 400 ng/g for all the analytes, except for THC glucuronide (10-400ng/g); intra-assay, inter-assay and total imprecision were <11.2%, <13.45% and <15.6%, respectively; accuracy ranged from 93.9% to 109.0% of the target concentration; matrix effect, extraction and process efficiency ranged from -26.4% to -71.4%, 49.9% to 69.5% and 14.3% to 45.0%, respectively. The inclusion of THC and THCCOOH glucuronides avoided the need for the hydrolysis process, thus facilitating sample pretreatment. Application of the method to 19 authentic meconium specimens from uncontrolled pregnancies or women suspicious of drug consumption revealed fetal cannabis exposure in 4 newborns. THCCOOH (24.1-288.8ng/g), diOHTHC (53.2-332.4ng/g), THC (4.2-7.7ng/g), CBN (30.7-93.3ng/g) and CBD (7.1-251.5ng/g) were detected in all cases; THCCOOH glucuronide (190.2-306.8ng/g) in 3 cases; and OHTHC (11.9ng/g) in the remaining one; however, THC glucuronide was not identified in any specimen.
authors.affiliation: Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain. Electronic address: pabloprego@hotmail.es.
authors.forename: Pablo
authors.initials: P
authors.lastname: Prego-Meleiro
authors.affiliation: Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain. Electronic address: elena.lendoiro@usc.es.
authors.forename: Elena
authors.initials: E
authors.lastname: Lendoiro
authors.affiliation: Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, NY, USA. Electronic address: mconcheiro-guisan@jjay.cuny.edu.
authors.forename: Marta
authors.initials: M
authors.lastname: Concheiro
authors.affiliation: Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain. Electronic address: angelines.cruz@usc.es.
authors.forename: Angelines
authors.initials: A
authors.lastname: Cruz
authors.affiliation: Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain. Electronic address: manuel.lopez-rivadulla@usc.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: López-Rivadulla
authors.affiliation: Toxicology Service, Institute of Forensic Sciences, University of Santiago de Compostela, Santiago de Compostela, Spain. Electronic address: ana.decastro@usc.es.
authors.forename: Ana
authors.initials: A
authors.lastname: de Castro
mesh_terms: D002186:Cannabinoids / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D002411:Cation Exchange Resins / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007231:Infant, Newborn; D057230:Limit of Detection; D008470:Meconium / Q000737:chemistry*; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
chemical_list: D002186:Cannabinoids; D002411:Cation Exchange Resins
keywords: Cannabis; Glucuronide; LC–MS/MS; Meconium; Metabolite