The passage of the US Farm Bill created legal pathways for farmers, processors and retailers to grow the hemp industry at a remarkable rate.  The Farm Bill exempted hemp and “any part of the plant, including the seeds thereof and all <b>derivatives</b>, extracts, cannabinoids, <b>isomers</b>…..” from the Controlled Substance Act.  In October of 2019, the USDA Interim Final Rule (IFR) provided additional clarification, again applying the 0.3% dry weight limit only to the total Δ9-THC concentration, exempting other isomers from the calculation of total tetrahydrocannabinol.  This created an unintended loophole for the emergence of Δ8-THC as a market alternative. Δ8-THC, with more limited psychoactive effects relative to its Δ9-THC cousin, is only found naturally in trace quantities in cannabis.  However it can be easily created by the semi-synthetic isomerization from the readily available and inexpensive CBD, extracted from compliant hemp biomass. However, the synthetic processes used for these conversions can be unpredictable, resulting in consumer products containing unintended side products, contaminants and isomers of THC. Recent FDA and CDC warnings highlight the potential danger of these products and report over 600 cases of serious adverse events from consumption of these products, many involving the use by minors.  To further complicate the landscape, as synthetic processes have become more normalized, we see new chemical compounds hitting the consumer market, including hexahydrocannabinol (HHC), Tetrahydrocannabiphorol (THCP), and Tetrahydrocannabinol-acetate (Δ9-THCO and Δ8-THCO), just to name a few.  These chemical compounds and their associated synthetic impurities, which do not occur naturally, have not been studied for efficacy or toxicity, potentially presenting risks to consumer safety. In addition, the HPLC methods typically used to assess purity of these consumer products are often inadequate in identification of these compounds and their impurities.  This presentation will discuss the synthetic pathways used in conversion, the complexity of resulting products, and the application of multiple orthogonal analytical approaches to identify impurities, including Liquid Chromatography (LC), Gas Chromatography (GC), and Supercritical Fluid Chromatography (SFC), coupled with UV or Mass Spectrometric detection.  This data will be presented against the changing regulatory landscape which will impact the commercialization of products containing these compounds.

Hemp derivatives and isomers: Exploitation of an unintended loophole

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.