Analysis of cannabis components by growth stage using solid-phase microextraction and solvent extraction

Abstract

 Illegal distribution of cannabis products, such as cannabis-infused foods and e-liquids, are increasing in Japan. The main component of cannabis is tetrahydrocannabinol (THC). THC extracted from cannabis is regulated by the Cannabis Control Act, and chemically synthesized THC is regulated by the Narcotics and Psychotropics Control Act; therefore, it is important to identify the source of THC for judicial appraisal. Recently, the crime of cultivating cannabis has occurred frequently in Japan. Illegal cultivation is difficult to discover because there are cases in which cannabis is cultivated secretly in a room in apartments, etc. Cannabis is a plant that emits unique odors. Detection of the odor constituents can provide a breakthrough for the criminal investigation of cannabis cultivation. The purpose of this study was to identify cannabis products and utilize them for the criminal investigation of cannabis cultivation. Cannabis plants were cultivated from seeds and analyzed using both solid-phase microextraction (SPME) and solvent extraction. Fifty kinds of volatile components were detected by SPME and 21 kinds of refractory components were detected by solvent extraction in fresh cannabis plants. We found that terpenes were detected more strongly in cannabis buds than in cannabis leaves. Furthermore, sesquiterpenes were strongly detected from cannabis leaves and monoterpenes were strongly detected from cannabis buds. The most abundant components were β-myrcene, cis-β-ocimene, terpinolene, β-caryophyllene, trans-α-bergamotene, humulene and β-farnesene. Additionally, THC, cannabichromene, cannabigerol and tetrahydrocannabivarin known as cannabinoids, were detected in all the samples. For the identification of cannabis products, 7 kinds of terpenes and 4 kinds of cannabinoids are promising combinations. Additionally, these terpenes may be useful in the criminal investigation of cannabis cultivation.