A rapid liquid-liquid extraction based presumptive test that differentiates between hemp and marijuana​


  • Brooke Underwood
  • Courtney LaPointe


Passage of the Farm Bill in December 2018 legalized cannabis containing less than 0.3% THC (Hemp). This creates problems for law enforcement since current presumptive test kits either 1) don’t work at all or 2) work somewhat in differentiating between legal and illegal hemp crops. This problem exists because most hemp crops and hemp products contain low levels of THCA and THC. Our approach involves the development of an efficient, mobile, liquid-liquid extraction that provides presumptive (qualitative) forensic evidence of the chemical extract of a bud or other plant material. The evidence would later be sent to a crime lab for definitive analysis of tetrahydrocannabinol (THC) content, the psychoactive compound in marijuana. This research has focused on the utilization of liquid-liquid extraction techniques and commercially available stains. The methods presented are rapid (requiring no more than five to six minutes to complete). The differentiation between two lots of commercially available hemp and seven lots of marijuana obtained from the Cookeville City Police will be presented.​