All ETDs from UAB

Advisory Committee Chair

Elizabeth Gardner

Advisory Committee Members

Jason Linville

Erin Shonsey

Document Type


Date of Award


Degree Name by School

Master of Science (MS) College of Arts and Sciences


Cannabis is the most commonly abused drug in the United States and the world. It contains at least 100 phytocannabinoids including tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), and cannabigerol (CBG), each of which produce different pharmacodynamics in the human body. Different isomers of THC are present in marijuana, of which Δ9-THC is the main psychoactive chemical. While many states have legalized medical and recreational use of cannabis, marijuana and many other cannabis derivatives remain Schedule I controlled substances federally and in many states including Alabama. Exceptions to these laws include hemp-derived products with a Δ9- THC content of no more than 0.3%. The prevalence of the use and abuse of THC isomers has increased in recent years as users continue to explore Δ9-THC alternatives such as Δ8-THC, (6aR, 9R)-Δ10-THC, (6aR,9S)-Δ10-THC, 9(R)-Δ6a,10a-THC, and 9(S)-Δ6a,10a-THC. This has resulted in an increase in the number of cannabinoid compounds being detected in seized materials. Thus, a validated method for identifying these cannabinoids is required to produce forensically defensible data that can be used in drugs charges. The purpose of this research is to validate a method for detecting nine cannabinoids: Δ9-THC, Δ8-THC, CBD, CBN, CBG, (6aR, 9R)-Δ10-THC, (6aR,9S)-Δ10- THC, 9(R)-Δ6a,10a-THC, and 9(S)-Δ6a,10a-THC. The validation parameters included limit iv of detection, reproducibility, and simulated casework. Interference was assessed to determine analytes that could prevent the proper identification of the nine cannabinoids. All analyses were conducted using gas chromatography/mass spectrometry (GC/MS). A secondary objective was to separate all nine cannabinoids from each other by at least 0.2 minutes, but this was not required for a successful validation. The limit of detection for all target cannabinoids was determined to be 5 μg/mL (Δ9-THC, CBN, and 9(R)-Δ6a,10a-THC), 10 μg/mL ((6aR,9R)-Δ10-THC and (6aR,9S)-Δ10- THC), or 50 μg/mL (Δ8-THC, CBD, CBG, and 9(S)-Δ6a,10a-THC). All reproducibility and simulated casework data met acceptance criteria. Ten interferents were identified. Additionally, it was determined that all nine cannabinoids could not be fully separated from one another with the GC/MS method used. Since all acceptance criteria were met for the reproducibility and simulated casework studies, and the limit of detection and interference were thoroughly assessed, the validation was successful.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.