Detection of the marijuana metabolite 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid in oral fluid specimens and its contribution to positive results in screening assays.
The detection of the marijuana metabolite 11-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in oral fluid specimens is described, and its contribution to an immunoassay for the detection of cannabinoids is investigated. Oral fluid specimens, screened using an enzyme-linked immunosorbent immunoassay (ELISA), were carried forward to confirmation for both tetrahydrocannabinol (THC) and THC-COOH using gas chromatography-mass spectrometry (GC-MS). One hundred and fifty-three specimens were analyzed, of which 143 screened positive for cannabinoids. Ninety-five (66.4%) of these specimens were positive for both THC and THC-COOH; 14 (9.7%) were positive for THC-COOH only, and 27 (18.8%) were positive for THC only. The GC-MS assay for the detection of THC-COOH in oral fluid was linear to 160 pg/mL with a limit of quantitation of 2 pg/mL. The detection of the marijuana metabolite, THC-COOH, in 76.2% of oral fluid specimens screening positive for cannabinoids is reported. As a potential defense against passive exposure claims, proposed SAMHSA regulations may require the simultaneous collection of a urine sample when oral fluid samples are used. The detection of the metabolite, THC-COOH, is a significant alternative to this approach because its presence in oral fluid minimizes the argument for passive exposure to marijuana in drug testing cases.
Moore
Christine
C
Immunalysis Corporation, 829 Towne Center Drive, Pomona, California 91767, USA. cmoore@immunalysis.com
Ross
Wayne
W
Coulter
Cynthia
C
Adams
Laura
L
Rana
Sumandeep
S
Vincent
Michael
M
Soares
James
J
D002186:Cannabinoids / Q000032:analysis* / Q000378:metabolism; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008385:Marijuana Smoking / Q000378:metabolism*; D009055:Mouth / Q000378:metabolism*; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry*; D015813:Substance Abuse Detection
D002186:Cannabinoids; C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol