Thin-layer chromatography presumptive test kit to qualify Cannabis plant material


  • Courtney LaPointe
  • Jeff Boles


The United States 2018 Farm Bill separated Cannabis production into two categories: marijuana and hemp. Clandestine marijuana is defined by more than 0.3% tetrahydrocannabinol (THC), and hemp is anything lower than that THC permitter. Cannabinoids are only identifiable at a molecular level which has become a problem for different agencies as the current presumptive forensic test kits can only test the presence of Cannabis. Developing a new presumptive test kit that can differentiate marijuana and hemp on a molecular level is pertinent to solving this issue for law enforcement and farmers both. Using thin layer chromatography (TLC), the plant material matrix is separated, and the individual cannabinoids are visible to the user. A polyester backed TLC plate, a moderately polar mobile phase and extraction fluid, and a commercial water-soluble stain allows the kit to be used in rugged environments. Time and temperature studies were conducted to simulate the real-life conditions. The method used successfully differentiated the cannabinoids in seven lots of marijuana and fifteen lots of hemp by staining CBD as an orange color and THC as a red. The kit being rapid, cost efficient, and simple to operate creates an opportunity for any person to use it. The low cost is advantageous for rural law enforcement and farmers and furthers Tennessee Tech's Grand Challenge focusing on the development of rural areas.