Urinary cannabinoid analysis: comparison of four immunoassays with gas chromatography-mass spectrometry.

Eight-eight urine samples were analysed by the EMIT d.a.u. Cannabinoid 20 ng homogeneous enzyme immunoassay, the DPC cannabinoid radioimmunoassay, two in-house cannabinoid radioimmunoassays and a gas chromatography-mass spectrometry method for 11-nor-9-carboxy-delta 9-tetrahydrocannabinol. There was good qualitative agreement between the methods with few discrepancies in the borderline region.

Gas chromatographic-mass spectrometric confirmation of radioimmunoassay results for cannabinoids in blood and urine.

A simple gas chromatographic-mass spectrometric (GC-MS) method is described for the detection of 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (delta 9-THC-COOH) in blood and urine samples found to be positive by two in-house cannabinoid radioimmunoassays (RIAs). The delta 9-THC-COOH in the samples, which is partly present as its glucuronide conjugate, is isolated by solvent extraction after hydrolysis of the glucuronide. It is converted to its trimethylsilyl derivative and analysed by capillary GC-MS in the electron impact mode with selected ion recording. All samples that were positive by both RIAs were also positive by GC-MS apart from four blood and two urine samples in which the GC-MS results were inconclusive owing to the presence of coextractives. No sample that was positive by both RIAs was found to be negative by GC-MS.

The gas chromatography mass spectrometry of the major metabolites of flurazepam.

Mass spectra and gas chromatographic data are presented for flurazepam and its metabolites; monodesethylflurazepam, didesethylflurazepam, hydroxyethylflurazepam, N1-desalkylflurazepam, N1-desalkyl-3-hydroxy-flurazepam, and flurazepam-N1-acetic acid. The on-column thermal degradation of didesethylflurazepam, N1-desalkyl-3-hydroxyflurazepam and flurazepam-N1-acetic acid is reported and discussed. Mass spectrometric and gas chromatographic data are also presented for the benzophenones obtained by acid hydrolysis of flurazepam and its metabolites. The occurrence of flurazepam metabolites in urine from five forensic cases after various treatments has been investigated. A possible new 'metabolite' of flurazepam was detected in two of these cases.