Temporal Indication of Marijuana Use Can Be Estimated From Plasma and Urine Concentrations of 9-Tetrahydrocannabinol, 11-Hydroxy- 9-Tetrahydrocannabinol, and 11-Nor- 9-Tetrahydrocannabinol-9-Carboxylic Acid

Estimating the time of last cannabis use from plasma delta9-tetrahydrocannabinol and 11-nor-9-carboxy-delta9-tetrahydrocannabinol concentrations.

BACKGROUND Knowing the time cannabis was last used is important for determining impairment in accident investigations and clinical evaluations. Two models for predicting time of last cannabis use from single plasma cannabinoid concentrations-model I, using Delta(9)-tetrahydrocannabinol (THC), and model II, using the concentration ratio of 11-nor-9-carboxy-THC (THCCOOH) to THC-were developed and...

Novel automated extraction method for quantitative analysis of urinary 11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH).

An automated extraction method for extracting the major urinary metabolite of cannabis, 11-nor-Delta(9)-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) was developed on the four-probe Gilson ASPEC XL4trade mark solid-phase extraction (SPE) system. The method works on liquid-liquid extraction principles but does not require the use of SPE cartridges. The limits of detection and quantitation an...

Distribution of ∆9-Tetrahydrocannabinol and 11-Nor-9-Carboxy-∆9-Tetrahydrocannabinol in Postmortem Biological Fluids and Tissues From Pilots Fatally Injured in Aviation Ac

Urinary excretion profiles of 11-nor-9-carboxy-delta 9-tetrahydrocannabinol in humans after single smoked doses of marijuana.

Interpretation of marijuana-positive urine tests requires an understanding of the excretion pattern of marijuana metabolites in humans. However, limited urinary excretion data from controlled clinical studies of marijuana use are available. In this study, six subjects smoked a single marijuana cigarette (placebo, 1.75% delta 9-tetrahydrocannabinol [THC], or 3.55% THC) each week while residing o...

Simplified analysis of 11-hydroxy-delta-9-tetrahydrocannabinol and 11-carboxy-delta-9-tetrahydrocannabinol in human meconium: method development and validation.

We describe the development of a sensitive analytical method for the analysis of 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC) and 11-carboxy-delta-9-tetrahydrocannabinol (THCC) in meconium using a gas chromatography-mass spectrometry (GC/MS) platform. The method was validated according to protocols, which included assessment of accuracy, precision, robustness, stability in meconium and i...