Determination of δ9-THC in whole blood using gas chromatography-mass spectrometry

Mark Hok Chi Chu, Olaf H. Drummer

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A simple and reliable liquid-liquid extraction method for the determination of Δ9-tetrahydrocannabinol (THC) in whole blood utilizing gas chromatography-mass spectrometry in electron impact mode is described. The substance is derivatized with pentafluoropropionic anhydride in pentafluropropanol. The limit of detection is 0.5 ng/mL for a 1-mL specimen, with recovery greater than 70%. The intra-assay coefficient of variation (CV) is 3.1% to 5.2%, and the interassay CV is 6.4% to 9.5%, calculated at THC concentrations of 1,5, and 25 ng/mL. The accuracy is between 95 and 97%. The optimization of extraction and derivatization conditions is detailed.

Original languageEnglish
Pages (from-to)575-581
Number of pages7
JournalJournal of Analytical Toxicology
Issue number8
Publication statusPublished - 2002

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