Simultaneous GC-EI-MS Determination of 9-Tetrahydrocannabinol, 11-Hydroxy- 9-Tetrahydrocannabinol, and 11-nor-9-Carboxy- 9-Tetrahydrocannabinol in Human Urine Following Tandem Enzyme-Alkaline Hydrolysis
| Autor: | Marilyn A. Huestis, Stephane O Pirnay, Tsadik T. Abraham, William D. Darwin, Ross H. Lowe |
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| Rok vydání: | 2007 |
| Předmět: |
Spectrometry
Mass Electrospray Ionization Analyte Health Toxicology and Mutagenesis Marijuana Smoking Alkaline hydrolysis (body disposal) Toxicology Article Gas Chromatography-Mass Spectrometry Analytical Chemistry chemistry.chemical_compound Enzymatic hydrolysis Humans Sodium Hydroxide Environmental Chemistry Dronabinol Solid phase extraction Derivatization Glucuronidase Psychotropic Drugs Chemical Health and Safety Chromatography Hydrolysis Reproducibility of Results BSTFA Substance Abuse Detection chemistry Gas chromatography Quantitative analysis (chemistry) |
| Zdroj: | Journal of Analytical Toxicology. 31:477-485 |
| ISSN: | 1945-2403 0146-4760 |
| Popis: | A sensitive and specific method for extraction and quantification of Delta(9)-tetrahydrocannabinol (THC), 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in human urine was developed and fully validated. To ensure complete hydrolysis of conjugates and capture of total analyte content, urine samples were hydrolyzed by two methods in series. Initial hydrolysis was with Escherichia coli beta-glucuronidase (Type IX-A) followed by a second hydrolysis utilizing 10N NaOH. Specimens were adjusted to pH 5-6.5, treated with acetonitrile to precipitate protein, and centrifuged, and the supernatants were subjected to solid-phase extraction. Extracted analytes were derivatized with BSTFA and quantified by gas chromatography-mass spectrometry with electron impact ionization. Standard curves were linear from 2.5 to 300 ng/mL. Extraction efficiencies were 57.0-59.3% for THC, 68.3-75.5% for 11-OH-THC, and 71.5-79.7% for THCCOOH. Intra- and interassay precision across the linear range of the assay ranged from 0.1 to 4.3% and 2.6 to 7.4%, respectively. Accuracy was within 15% of target concentrations. This method was applied to the analysis of urine specimens collected from individuals participating in controlled administration cannabis studies, and it may be a useful analytical procedure for determining recency of cannabis use in forensic toxicology applications. |
| Databáze: | OpenAIRE |
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