Research and Development Using High-level Quantum Chemistry Calculations for the Creation of a Rapid Field Test for the Identification and Differentiation of Hemp and Marijuana

The Department of Justice has identified several areas that require focused attention to improve criminal justice practice in the seized drugs discipline, including development of a “field test for discrimination of hemp versus marijuana”. This is necessary because hemp and marijuana plants are simply variants of the same species, Cannabis sativa, making them difficult to differentiate from one another. While both varieties contain THC, marijuana and hemp differ in the amount of this psychoactive molecule present. Federal laws define C. sativa with >0.3% THC as the illegal drug-type (i.e., marijuana), while material with ≤0.3% is the legal fiber-type (i.e., hemp). This definition has imposed severe challenges on crime labs, including the dramatic increase in workload that results from the need to analyze and quantify the THC content of incoming C. sativa samples so that seized material can be appropriately designated. Therefore, a method to triage C. sativa plant material in the field is urgently needed.

This project seeks to develop a screening method to differentiate between hemp and marijuana. The development of an approach to rapidly distinguish between these C. sativa varieties would aid forensic investigation and triage of evidence prior to submission to forensic laboratories for confirmatory testing. This project leverages the power of high-level computational chemistry calculations for predicting the spectroscopic characteristics of cannabinoid/metal complexes, and uses the information gleaned to create a reagent that, when combined with C. sativa, will register a colorimetric or fluorescence response (when exposed to UV light of appropriate wavelength) that will be distinct for marijuana versus hemp. This project will assess the binding interactions of cannabinoids with metals using computational calculations, at a high level of theory, for prediction of those that will yield differential color, UV-Vis and/or fluorescence characteristics (Specific Aim I). These high-level quantum calculations will inform the experimental assessment of the differential color and fluorescence characteristics of cannabinoid/metal binding (including THC/Metal and CBD/Metal pairs) (Specific Aim II). To our knowledge, this will be the first method that utilizes computational chemistry to inform experimental design regarding forensic science research. The main anticipated outcome will be the creation of a preliminary test with high sensitivity and specificity to distinguish hemp and marijuana, which will ultimately aid forensic practitioners in decreasing testing backlogs. Semi-annual and final progress and financial reports, as well as scholarly products (e.g., peer-reviewed articles) will be produced. CA/NCF