title: Simultaneous determination of Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in oral fluid using isotope dilution liquid chromatography tandem mass spectrometry.
abstract: The detection and confirmation of cannabinoids in oral fluid are important in forensic toxicology. Currently, the presence of Δ(9)-tetrahydrocannabinol (THC) is used for the detection of cannabis in oral fluid. A low concentration of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THC-COOH) is found in oral fluid, which suggested a convenient and low-sensitivity confirmation assay can be used in a routine forensic laboratory. In this study, a highly sensitive isotope dilution liquid chromatography-tandem mass spectrometry method following dansylation was successfully developed for simultaneous determination of THC and THC-COOH in oral fluid. The dansylated derivatives dramatically demonstrated and enhanced the sensitivity of THC and THC-COOH. To avoid signal influenced by the matrix, a 5-min liquid chromatography gradient program was evaluated and optimized, which reduced the sample diffusion and caused sharp peaks (less than 12 s) and thus helped to achieve detection at a low level. The sensitivity, accuracy, and precision were also evaluated, and high quantitative accuracy and precision were obtained. The limit of quantitation of this approach was 25 pg/mL for THC and 10 pg/mL for THC-COOH in oral fluid. Finally, the method was successfully applied to eight suspected cannabis users. Among them, in six oral fluid samples THC-COOH was determined at a concentration from 13.1 to 47.2 pg/mL.
authors: Institute of Medical and Molecular Toxicology, Chung Shan Medical University, Taichung, Taiwan.
authors: Pin Duo
authors: PD
authors: Lee
authors: Yuan-Jhe
authors: YJ
authors: Chang
authors: Keh-Liang
authors: KL
authors: Lin
authors: Yan-Zin
authors: YZ
authors: Chang
mesh_terms: D002851:Chromatography, High Pressure Liquid; D013759:Dronabinol / Q000031:analogs & derivatives / Q000032:analysis*; D006801:Humans; D007201:Indicator Dilution Techniques; D007553:Isotope Labeling; D012463:Saliva / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D013759:Dronabinol