title: Gas chromatographic-mass spectrometric quantitation of urinary 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid after derivatization by direct extractive alkylation.
abstract: A gas chromatographic-mass spectrometric procedure for the quantitation of urinary 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) has been developed in which the THC-COOH was derivatized to its corresponding methyl ester-methyl ether derivative by direct extractive alkylation using tetrahexylammonium (THA+) counter-ion and iodomethane dissolved in toluene. The procedure utilised a sample volume of 2 ml and gave a detection limit of 0.25 ng/ml. The inter-run and intra-run coefficients of variation were 7.0% and 4.8%, respectively. The inter-day standard curves were linear in the concentration range 0-300 ng/ml with a mean r = 0.9997 (n = 4).
authors.affiliation: Australian Government Analytical Laboratories, Pymble, N.S.W.
authors.forename: A M
authors.initials: AM
authors.lastname: Lisi
authors.forename: R
authors.initials: R
authors.lastname: Kazlauskas
authors.forename: G J
authors.initials: GJ
authors.lastname: Trout
mesh_terms: D000478:Alkylation; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D006868:Hydrolysis; D015203:Reproducibility of Results
chemical_list: C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol