All ETDs from UAB

Advisory Committee Chair

Elizabeth Gerdner

Advisory Committee Members

Curt E Harper

Amanda Stafford

Document Type


Date of Award


Degree Name by School

Master of Science (MS) College of Arts and Sciences


Oral fluid (OF) drug testing has been expanded to laboratory evidentiary confirmation testing in driving under the influence (DUI) cases. OF samples are collected by officers at the roadside using collection devices such as the Quantisal® device. Tetrahydrocannabinol (Δ9-THC) was the most prevalent drug in Alabama DUI casework in 2022. Δ9-THC remains a Schedule I drug in Alabama and federally. Current validated targets in cannabinoid oral fluid testing include Δ9-THC, Δ8-THC, 9R-Δ10-THC, 9S-Δ10-THC 11-hydroxy-Δ9-THC (THC-OH), 11-nor-9-carboxy-Δ9-THC (THC-OOH), cannabigerol (CBG), cannabidiol (CBD), and cannabinol (CBN). Due to the 2018 Farm Bill, cannabinoids derived from hemp with a Δ9-THC concentration less than 0.3% are legal in Alabama. This has caused novel cannabinoids such as tetrahydrocannabinol-acetate (THC-O) and tetrahydrocannabiphorol (THC-P) to be manufactured and sold legally. Methods need to be developed to ensure these legal cannabinoids can be distinguished from Δ9-THC during confirmatory testing. This study validated THC-O and THC-P to add to the oral fluid extraction method in use at the Alabama Department of Forensic Sciences (ADFS). Understanding cannabinoid stability is important as it is common for long periods of time to pass between collection of a sample and analysis. Several factors affect cannabinoid stability such as storage temperature, light conditions, and volume of solution a drug is in. This study examined how cannabinoid stability is affected when oral fluid samples are stored at 20°C (room temperature), 4°C (refrigeration), -20°C, or in the trunk of a car at varying time points. Samples were also subjected to different light conditions during storage. Δ9-THC concentrations were considered stable if the concentration at time of reanalysis was within 20% of the initial concentration. Average Δ9-THC concentrations in OF remained stable after one month when samples were stored at 4°C or -20°C. Samples did not remain stable at 4°C when exposed to light or when samples were at low volumes prior to analysis. Storing samples in the trunk of a car led to Δ9-THC instability after one week of storage at 31°C. Samples were stable in glass and plastic. Quantisal® buffer was stable when stored at 32°C for seven days prior to collection of OF.



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