Absorbance-Transmittance Excitation Emission Matrix Method for Quantification of Major Cannabinoids and Corresponding Acids: A Rapid Alternative to Chromatography for Rapid Chemotype Discrimination of Cannabis sativa Varieties

Abstract Background: Phytocannabinoids naturally occur in the cannabis plant (Cannabis sativa), and Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) predominate. There is a need for rapid inexpensive methods to quantify total THC (for statutory definition) and THC–CBD ratio (for classification into three chemotypes). This study explores the capabilities of a spectroscopic technique that combines ultraviolet-visible and fluorescence, absorbance-transmittance excitation emission matrix (A-TEEM). Methods: The A-TEEM technique classifies 49 dry flower extracts into three C. sativa chemotypes, and quantifies the total THC–CBD ratio,