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Clinical Chemistry, Vol 37, 2062-2068, Copyright © 1991 by American Association for Clinical Chemistry
LM Shaw, J Edling-Owens and R Mattes
Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia 19104.
Plasma concentrations of delta-9-tetrahydrocannabinol, the principal psychoactive cannabinoid in marijuana, decline to values substantially less than 1 microgram/L within a few hours after a subject has smoked a marijuana cigarette. Using a single-quadrupole gas chromatograph-mass spectrometer (GC/MS) operated in the negative chemical-ionization mode and retrofitted with a High Energy Dynode detector system, we measured delta-9-tetrahydrocannabinol and a primary metabolite, 11-nor-delta-9- tetrahydrocannabinol-9-COOH. Using a trifluoroacetic anhydride derivatization procedure and the High Energy Dynode detector system, we improved by 6.25-fold the limit of detection for delta-9- tetrahydrocannabinol in plasma over that obtained with the same GC/MS system without the new detector (80 vs 500 ng/L). The new detector system will thus permit further investigation of the post-distribution pharmacokinetics of delta-9-tetrahydrocannabinol and detection of delta- 9-tetrahydrocannabinol in plasma for a longer time after ingestion of the drug in forensic cases. The High Energy Dynode detector system should be applicable to a wide variety of other GC/MS analyses that require significantly improved sensitivity.
The following articles in journals at HighWire Press have cited this article:
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J. A. Grisso, D. F. Schwarz, N. Hirschinger, M. Sammel, C. Brensinger, J. Santanna, R. A. Lowe, E. Anderson, L. M. Shaw, C. A. Bethel, et al. Violent Injuries among Women in an Urban Area N. Engl. J. Med., December 16, 1999; 341(25): 1899 - 1905. [Abstract] [Full Text] [PDF] |
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