• Hayes, Eugene D.
• Cone, Edward J.
• Flegel, Ronald

Abstract

Background and aim: Δ8-tetrahydrocannabinol (Δ8-THC) is a minor metabolite in cannabis but can also be produced by chemical modification of CBD extracted from hemp. The main urinary metabolite of Δ8-THC is the carboxylic acid metabolite (Δ8-THC-COOH).<br/>In the US, Δ8-THC products are widely available in stores and online, and are generally perceived as legal. Dosing studies indicate that Δ8-THC effects are similar to Δ9-THC, makingΔ8-THC a workplace safety concern.<br/>The aim of this study was to estimate the prevalence of Δ8-THC use by applicants and employees in federally mandated drug testing programs, typically in safety sensitive positions.<br/>Methods: The concentration of 15 cannabinoids and metabolites, including Δ8-THC-COOH and Δ9-THC-COOH, were determined by LC-MS/MS in 1,504 deidentified urine specimens with a positive immunoassay result for cannabinoids, using an assay with a 50 ng/mL Δ9-THC-COOH cutoff and &gt;80% cross-reactivity for Δ8-THC-COOH. The specimens were obtained in 2022 from applicants or current employees for safety or security sensitive positions in federally mandated testing programs.<br/>Results: Δ8-THC-COOH and Δ9-THC-COOH were detected (≥15 ng/mL) in 1,144 and 378 specimens, respectively. In 123 specimens, only Δ8-THC-COOH was detected, indicating that positivity for cannabinoids would increase by an estimated 11%, if Δ8-THC-COOH was added to the scope of testing. Based on 2022 data, estimated prevalence of Δ8-THC-COOH as a single drug is estimated to be0.10% in urine specimens for those subject to federally mandated drug testing. . This would make Δ8-THC one of the most prevalent drugs, only eclipsed by Δ9-THC (0.94%), amphetamines (0.78%), andcocaine (0.20%),.<br/>The median concentration in Δ8-THC-COOH and Δ9-THC-COOH dominant (at least 90% of the dominant isomer) specimens were 150 and 187 ng/mL, respectively. This indicates similarities in both potency and metabolism, and that cutoffs and testing schemes currently used for Δ9-THC-COOH could be used for Δ8-THC-COOH.<br/>Conclusion: Δ8-THC is currently one of the most frequently used drugs in the US workforce. Use can be detected by urinary immunoassay screening, followed by LC-MS/MS confirmation using the same cutoffs as used for Δ9-THC-COOH.<br/>

Topics

• impedance spectroscopy
• liquid chromatography
• carboxylic acid
• liquid chromatography-mass spectrometry