Problems of Forensic Sciences 2007 Vol. 70 (LXX) 173-186
ANALYSIS OF Δ9-THC AND ITS METABOLITES: 11-OH-Δ9-THC AND THC-COOH IN BLOOD BY GAS CHROMATOGRAPHY COUPLED TO TANDEM MASS SPECTROMETRY (GC-MS-MS) AND ITS APPLICATION TO MEDICO-LEGAL INVESTIGATIONS
Sebastian ROJEK, Małgorzata KŁYS
Department of Forensic Medicine, Collegium Medicum, Jagiellonian University, Krakow, Poland
Streszczenie
Polish legal regulations, especially those concerning road traffic safety mean that forensic toxicologists are required to perform qualitative and quantitative analysis of active ingredients of Cannabis, i.e. Δ9-tetrahydrocannabinol (Δ9-THC) and its metabolites in biological specimens. Analytical criteria regarding determination of these compounds in blood are specified in the Decree of the Minister of Health (Journal of Laws 2003, no.116, item 1106, and Journal of Laws 2004, no. 52, item 524). In this study the authors presented application of their procedure for determination of Δ9-tetrahydrocannabinol (Δ9-THC), as well as its two metabolites, 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-Δ9-THC) and 11-nor-9-carboxy-Δ9-tetrahydrocannabinolic (THC-COOH) acid, in ante-mortem and post-mortem blood specimens by means of gas chromatography coupled to tandem mass spectrometry in electron impact mode (GC-EI-MS-MS). Method validation was performed according to ISO 17025:2005. The limit of detection (LOD) and limit of quantification (LOQ) were 1 ng/ml for Δ9-THC and 11-OH-THC, and 5 ng/ml for THC-COOH. The linearity of the method (LOL) was within the 1–50 ng/ml range for 9-THC and 11-OH-THC, and 5–100 ng/ml for THC-COOH. Inter-assay and intra-assay precision and relative error values were in the range of 6.8–12.3 and 7.0–15.5%, respectively. The analytes’ extraction recoveries were in the range of 68.7–84.1%. The developed method is illustrated by two examples of analyses of blood specimens (collected ante-mortem and post-mortem) from toxicological practice.
Słowa kluczowe
Cannabinoids; Biological matrix; Blood; GC-MS-MS.