Detection of delta-9-tetrahydrocannabinol (THC) in oral fluid, blood and urine following oral consumption of low-content THC hemp oil.

Hemp-derivative (Cannabis sativa L.) food products containing trace levels of Δ-9-tetrahydrocannabinol (THC) are proposed for consumption in Australia and New Zealand; however, it is unclear whether use of these products will negatively affect existing drug screening protocols. This double-blind, within-subjects, cross-over trial assessed 35 adults (17 male; 18 female), aged 22-52 years [Mean=30.7, Standard Deviation (S.D)±7.6]. Low dose THC oil [5mL bearer sesame oil containing 10mg/kg THC (0.046mg THC per 5mL dose)]; high dose THC oil [5mL bearer sesame oil containing 20mg/kg THC (0.092mg THC per 5mL dose)]; and a placebo oil (THC negative) was consumed during a three-week protocol. The Securetec Drugwipe® II Twin device assessed THC presence (cut-off 20ng/mL) in oral fluid at baseline, at 5, 30, 60, 120 and 240min post-treatment. Blood was drawn at baseline, 30, 120 and 240min post-treatment, and urine at baseline and 240min post-treatment. No THC was detected in oral fluid, blood or urine samples at any time-point following consumption of the low or high THC dose. Trace concentrations of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (THCa) were detected in blood 4-h after consumption of the high THC treatment (M=0.0001mg/L) and in urine at 4-h post consumption of both low and high THC treatments (M=0.0001mg/L and 0.0004mg/L, respectively). Consumption of low-content THC oil does not result in positive biological assessments. It is therefore highly unlikely that ingestion of products containing these levels of THC will negatively impact existing region-specific drug driving enforcement protocols.

A rapid and sensitive method for the identification of delta-9-tetrahydrocannabinol in oral fluid by liquid chromatography-tandem mass spectrometry.

A fast and sensitive method was developed for detecting delta-9-tetrahydrocannabinol (THC) in oral fluid by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method is suitable for samples of small volume and low concentration. For method development and validation, neat oral fluid (200 µL) spiked with THC and d(3)-THC (internal standard) was extracted via liquid-liquid extraction (LLE). The LLE method had an extraction efficiency of 75% with no significant matrix effects observed in either diluted or neat oral fluid samples. LC was performed on a Zorbax Eclipse XDB-C18 Rapid Resolution HT column (2.1 mm × 50 mm, 1.8 µm particle size) with positive electrospray ionisation and selected reaction monitoring. The total run time was an efficient 3.5 min in isocratic elution mode. The limit of quantification was 1 ng/mL and the analysis was linear over the range of 1-500 ng/mL with a correlation coefficient of 0.9998. The imprecision (RSD) of the method was 13% and inaccuracy (MRE) was 4%. The method was subsequently applied to two neat oral fluid samples taken from a chronic cannabis smoker. It was also applied to buffer diluted residual oral fluid samples (n=48) collected using the Cozart RapiScan(®) system through the Roadside Drug Testing Program (RDTP) in NSW, Australia. A stability study was performed that revealed freezing or refrigerating resulted in comparable decreases in THC recovery from neat oral fluid at the end of two weeks of storage. Storage at room temperature even for one day invoked significant losses and is not recommended.