Date of Award
Ph.D. in Chemistry
University of Mississippi
The main objective of this study is to modify, develop, and validate techniques for detecting and quantifying the levels of major and minor cannabinoids, along with their corresponding acids, in Cannabis sativa plants and certain marketed products. To achieve this goal, the research employs Gas Chromatography (GC), High-Performance Liquid Chromatography (HPLC), and a novel spectroscopic method known as Absorbance-Transmittance Excitation Emission Matrix Spectroscopy (A-TEEM). Another study validated and applied the HPLC technique to analyze the unique class of flavonoids (Cannflavins) found in various parts of the cannabis plant, including leaves, buds, and pollen.
The A-TEEM method was developed and validated for the analysis of major cannabinoids in different cannabis chemovars. The method is rapid, sensitive, and comparable to traditional methods such as GC-FID and HPLC. XGB Discriminant Analysis can distinguish between legal and illegal chemotypes, while XBD regression can quantify total THC and total CBD levels with reference data comparable to GC-FID and HPLC.
An HPLC-PDA method was developed and validated to analyze 15 cannabinoids in cannabis plant materials and cannabis-based marketed products. The method was found to be linear, sensitive, and provided good baseline separation of cannabinoids. The LOD ranged from 0.2-1.6 μg/mL, and LOQ ranged from 0.6-4.8 μg/mL. Average recoveries for all cannabinoids were between 81%–104%.
A validated HPLC-PDA method was employed to investigate the distribution of cannflavins in different cannabis and hemp plants at various growth stages. CF-A was found to be the most abundant cannflavin detected in the samples, ranging from 15.2 ppm to 478.38 ppm. The method was accurate and precise, with all investigated cannflavins exhibiting a linear relationship in the range of 5–500 ppm with R2 > 0.99.
GC-MS was used to analyze 15 neutral and acid cannabinoids in various cannabis-derived products. The method demonstrated a limit of detection (LOD) and limit of quantification (LOQ) in the range of 0.1–0.25 μg/mL and 0.3–0.75 μg/mL, respectively. The accuracy (% recoveries) ranged from 93–118% with precisions ≤ 7.59%. The method was applied to determine cannabinoid content in 15 cannabis plant materials and 37 cannabis-derived products.
Elhendawy, Mostafa, "Development and Validation of Different Analytical Techniques for the Quantification of Cannabinoids and Cannflavins In Cannabis and Cannabis-Based Products" (2023). Electronic Theses and Dissertations. 2496.
Available for download on Friday, September 13, 2024