title: Quantitative analysis of 11-nor-9-carboxy-tetrahydrocannbinol (THC-COOH) in urine by LC-MS/MS following a simple filtration.
abstract: Quantification methods utilizing liquid chromatography tandem mass spectrometry (LC-MS/MS) are common in clinical and forensic toxicology laboratories and the efficiency and rapidity of such methods continues to evolve. In most cases, urine drug confirmation does not require a drug extraction and can quickly and easily be accomplished with a dilution followed by sample filtration. The report describes the validation of a simple confirmation method for 11-nor-9-carboxy-tetrahydrocannabinol (THC-COOH) and compared two types of filter extraction columns for sample clean-up. The method achieved a linear range of 10-3000ng/mL, acceptable bias (-4.7-2.6%) and precision (0.9-6.9%) and autosampler stability up to 72h. Universal filter columns offered less variable recovery over the linear range and fewer matrix interferences compared to THC-COOH specific filter columns. Authentic specimens testing positive for THC-COOH by LC-MS/MS were in good agreement with typically used GC-MS methods.
authors.affiliation: University of Florida College of Medicine, Department of Pathology, Immunology and Laboratory Medicine, Gainesville, FL 32608, USA. Electronic address: mrumpler@ufl.edu.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Rumpler
mesh_terms: D000704:Analysis of Variance; D002853:Chromatography, Liquid / Q000379:methods*; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000652:urine; D005374:Filtration / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol
keywords: Filtration; LC–MS/MS; THC–COOH