title: Solid-phase extraction of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid from human urine with gas chromatographic-mass spectrometric confirmation.
abstract: A selective and sensitive technique has been developed for detecting and identifying 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in human urine. Using a new, "mixed-mode", bonded silica gel, solid-phase extraction column cartridge, THC-COOH was selectively isolated from urine components. Following extraction, the presence of THC-COOH was confirmed and quantitated using gas chromatography-mass spectrometry (GC-MS) or gas chromatography-flame ionization detection. A linear quantitative response curve for THC-COOH was generated over a concentration range of 10 to 300 ng/ml. Overall extraction efficiency averaged greater than 85% and the quantitative response curve exhibited a correlation coefficient of 0.999. The limit of detection and identification using GC-MS for the drug metabolite was found to be six times below the present NIDA guidelines cut-off concentration of 15 ng/ml.
authors.affiliation: Varian Sample Preparation Products, Harbor City, CA 90710.
authors.forename: V
authors.initials: V
authors.lastname: Dixit
authors.forename: V M
authors.initials: VM
authors.lastname: Dixit
mesh_terms: D002849:Chromatography, Gas; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000652:urine; D005410:Flame Ionization; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007477:Ions
chemical_list: D007477:Ions; C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol