Hint in the Print: The Determination of Cannabis-use Biomarkers in Fingerprint Residues Using High-resolution Mass Spectrometry

Cannabis sativa is the most widely used controlled substance in the world. Although it is becoming increasingly legal at the state level, there are instances where it is important to know if an individual has consumed Cannabis, such as in the event of an accidental consumption case or workplace accident. Techniques for the definitive determination of Cannabis ingestion require the invasive collection of blood or urine, making the analysis unsuitable for field deployment, such as at a traffic stop. This research seeks to develop a less invasive and field deployable method for the determination of Cannabis use through the detection of Cannabis metabolites in fingerprint residues using high-resolution mass spectrometry. Fingerprint residue samples collected from donors who had consumed Cannabis via inhalation or the oral route and donors who had not consumed Cannabis were solubilized, and their chemical profiles were analyzed using direct analysis in real time – high-resolution mass spectrometry (DART-HRMS). The mass spectral data from the two experimental groups were compared using machine learning models to identify m/z values that can differentiate Cannabis use from non-use. Several models with good cross validation accuracies were created. A list of 14 m/z values that were found to be important for enabling the model to differentiate between Cannabis use and non-use was generated. Future work will focus on determining the identity of these 14 m/z values to assess their potential utility as Cannabis-consumption-specific biomarkers. These compounds can then serve as the basis for a field-deployable test for Cannabis use.