Industrial hemp is legally defined in the United States by the Agriculture Improvement Act of 2018 (2018 Farm Bill) as Cannabis containing <0.3% total tetrahydrocannabinol (THC). The 2018 Farm Bill does not, however, specify standard methods for sample preparation or quantification of cannabinoids (including THC) in Cannabis. Extraction efficiency of phytochemicals is well-known to depend on the solvent and extraction method used. In this project, we evaluated the effect of sample preparation extraction methods on the quantitative analysis of five cannabinoids found in industrial hemp with regulatory or commercial significance: cannabidiol (CBD), cannabidiolic acid (CBDA), delta-9-tetrahydrocannabinol (THC), tetrahydrocannabinolic acid (THCA), and cannabinol (CBN). Extraction methods evaluated include: QuEChERS, diethyl ether, ethanol, and methanol. Extracts obtained via these methods were subject to quantitative cannabinoid analysis by UPLC/PDA. Standard curves for quantification of each cannabinoid were constructed using authentic standards for quantification. The concentrations of each cannabinoid in the plant material determined via each of the extraction methods were compared using one-way ANOVA followed by Tukey's HSD (significant difference defined as p <0.05). All extraction methods evaluated returned different concentrations of total THC in the plant material. The QuEChERS extraction resulted in the highest calculated concentrations of THC, THCA and CBDA, reporting three to four times greater than obtained via other extractions evaluated. Classification of the starting plant material as hemp or marijuana depended on the extraction method used. These findings clearly and quantitatively demonstrate the need for standardization of extraction methods for hemp analysis and regulation. / Master of Science in Life Sciences / Hemp is a type of Cannabis plant that produces an insignificant amount of the psychoactive cannabinoid tetrahydrocannabinol (THC). Hemp was federally illegal in the United States until the 2018 Farm Bill differentiated hemp from Marijuana, defining hemp as containing less than 0.3% total THC. Standard methods for cannabinoid testing in hemp have not been defined. In this project, four extraction methods with potential use for sample preparation in hemp analysis were evaluated and compared. The extraction methods evaluated included: ethanol, methanol, QuEChERS, and diethyl ether. The concentrations of cannabinoids in each of the plant extracts were then determined using an appropriate analytical method and authentic standards for Cannabidiol (CBD), Cannabidiolic Acid (CBDA), THC, Tetrahydrocannabinolic Acid (THCA), and Cannabinol (CBN). Total concentrations of each cannabinoid in the plant material were then calculated using each extraction method. All extraction methods evaluated resulted in different concentrations of total THC in the plant material, with QuEChERS resulting in the highest calculated concentrations of THC, THCA, and CBDA. The identify of this plant material as hemp or marijuana depended on the extraction method used. This result is not surprising, as extraction efficiency of phytochemicals is well known to depend on the solvent and extraction method used. Nonetheless, our findings clearly demonstrate the need for standardization of extraction methods for hemp analysis and regulation.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/112677 |
| Date | 28 May 2021 |
| Creators | Sandbrook, Ann Marie |
| Contributors | Food Science and Technology, Stewart, Amanda C., O'Keefe, Sean F., Lahne, Jacob |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International, http://creativecommons.org/licenses/by-nc-nd/4.0/ |
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