title: Molecularly imprinted polymer for selective determination of Δ9-tetrahydrocannabinol and 11-nor-Δ9-tetrahydrocannabinol carboxylic acid using LC-MS/MS in urine and oral fluid.
abstract: The use of molecularly imprinted polymers (MIPs) for solid phase extraction (MISPE) allows a rapid and selective extraction compared with traditional methods. Determination of Δ(9)-tetrahydrocannabinol (THC) and 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH) in oral fluid (OF) and urine was performed using homemade MISPEs for sample clean-up and liquid chromatography tandem mass spectrometry (LC-MS/MS). Cylindrical MISPE shaped pills were synthesized using catechin as a mimic template. MISPEs were added to 0.5 mL OF or urine sample and sonicated 30 min for adsorption of analytes. For desorption, the MISPE was transfered to a clean tube, and sonicated for 15 min with 2 mL acetone:acetonitrile (3:1, v/v). The elution solvent was evaporated and reconstituted in mobile phase. Chromatographic separation was performed using a SunFire C18 (2.5 μm; 2.1 × 20 mm) column, and formic acid 0.1% and acetonitrile as mobile phase, with a total run time of 5 min. The method was fully validated including selectivity (no endogenous or exogenous interferences), linearity (1-500 ng/mL in OF, and 2.5-500 ng/mL in urine), limit of detection (0.75 and 1 ng/mL in OF and urine, respectively), imprecision (%CV <12.3%), accuracy (98.2-107.0% of target), extraction recovery (15.9-53.5%), process efficiency (10.1-46.2%), and matrix effect (<-55%). Analytes were stable for 72 h in the autosampler. Dilution 1:10 was assured in OF, and Quantisal™ matrix effect showed ion suppression (<-80.4%). The method was applied to the analysis of 20 OF and 11 urine specimens. This is the first method for determination of THC and THC-COOH in OF using MISPE technology.
authors.affiliation: Servicio de Toxicología, Instituto de Ciencias Forenses, Universidad de Santiago de Compostela, San Francisco s/n, 15782, Santiago de Compostela, Spain, elena.lendoiro@usc.es.
authors.forename: E
authors.initials: E
authors.lastname: Lendoiro
authors.forename: A
authors.initials: A
authors.lastname: de Castro
authors.forename: H
authors.initials: H
authors.lastname: Fernández-Vega
authors.forename: M C
authors.initials: MC
authors.lastname: Cela-Pérez
authors.forename: J M
authors.initials: JM
authors.lastname: López-Vilariño
authors.forename: M V
authors.initials: MV
authors.lastname: González-Rodríguez
authors.forename: A
authors.initials: A
authors.lastname: Cruz
authors.forename: M
authors.initials: M
authors.lastname: López-Rivadulla
mesh_terms: D000096:Acetone / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D001826:Body Fluids; D002138:Calibration; D002853:Chromatography, Liquid; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000032:analysis* / Q000652:urine*; D053593:Forensic Toxicology / Q000379:methods; D006801:Humans; D006868:Hydrolysis; D011108:Polymers / Q000737:chemistry*; D011786:Quality Control; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D012997:Solvents / Q000737:chemistry; D015813:Substance Abuse Detection / Q000379:methods; D053719:Tandem Mass Spectrometry; D016482:Urinalysis
chemical_list: D000097:Acetonitriles; D011108:Polymers; D012997:Solvents; D000096:Acetone; C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol; C032159:acetonitrile