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Proof of active cannabis use comparing 11‐hydroxy‐∆9‐tetrahydrocannabinol with 11‐nor‐9‐carboxy‐tetrahydrocannabinol concentrations
Author(s) -
Franz Thomas,
Skopp Gisela,
Schwarz Gerlinde,
Musshoff Frank
Publication year - 2018
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.2415
Subject(s) - tetrahydrocannabinol , dronabinol , cannabis , δ9 tetrahydrocannabinol , chemistry , cannabidiol , pharmacology , delta 9 tetrahydrocannabinol , cannabinoid , medicine , psychiatry , biochemistry , receptor
Testing hair for cannabis use has increasingly been scrutinised due to exposure to second‐hand smoke or environmental contamination. Confirmation of drug use involving detection of metabolites such as 11‐nor‐9‐carboxy‐delta‐9‐tetrahydrocannabinol (THC‐COOH) and 11‐hydroxy‐delta‐9‐tetrahydrocannabinol (THC‐OH) having very rarely been considered. We developed a new, simplified procedure with regard to expenditure of time and material to determine delta‐9‐tetrahydrocannabinol (THC, qualitatively), as well as THC‐OH and THC‐COOH (quantitatively) from 587 hair samples by liquid chromatography–tandem mass spectrometry (LC–MS/MS) which was compared to hitherto established methods ( n = 3). Compared to conventional methanolic extraction alkaline dissolution resulted in higher concentrations for THC‐OH. Concentrations determined from specimens ranged from 0.01 to 18.7 ng THC/mg hair, 0.05–37.6 pg THC‐OH/mg hair, and from 0.1 to 54.3 pg THC‐COOH/mg hair. THC was detectable in 70.4% samples along with both metabolites from more than half of these samples. In 12.9% of THC‐positive cases, neither THC‐OH nor THC‐COOH were present. In 8.9% of THC‐negative cases, it was possible to detect metabolites either alone or in combination. THC‐OH could more frequently be detected than THC‐COOH and appeared to be less susceptible to cosmetic treatment. In summary, THC‐OH turned out to be a further suitable marker to prove cannabis use. Determination of both metabolites is recommended to unequivocally differentiate consumption from external exposure or contamination.