Despite marijuana being the most widely used illicit drug in the U.S., there are no non-invasive on-site field-deployable tests for routine determination of marijuana ingestion. While many methods are being investigated to test for this more efficiently, they suffer from various draw backs and are generally not practical for field deployment. Therefore, it remains highly desirable to have a test for marijuana ingestion that differentiates between: (1) an individual who has not used the substance at all; (2) a person who has handled it (e.g., with their hands or been exposed to it in their immediate environment) but not ingested it; and (3) a person who has ingested it. It is possible that chemical markers indicative of marijuana ingestion are detectable in fingerprint residues. Therefore, it is proposed here that direct analysis in real time – high-resolution mass spectrometry (DART-HRMS) can be used to readily access this information, while additional knowledge can be obtained using chemometrics and matrix assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI). In this proposal, fingerprint residues from volunteers will be interrogated by DART-HRMS, followed by advanced statistical analysis of the mass spectral data to distinguish between individuals who have either consumed, handled, or neither consumed/handled marijuana, in order to reveal the variables (m/z values) that enable this differentiation (Specific Aim I). MALDI-MSI will be used to assess which of the m/z values indicative of marijuana ingestion are restricted to the ridge details of fingerprints (revealing an ion image of the respective print) and are therefore unique biomarkers produced by the body after consuming marijuana (Specific Aim II). The identities of these biomarkers will be determined using chromatographic and structural characterization methods (e.g., GC-MS, NMR, IR) (Specific Aim III). Once these molecules have been identified, future work can be directed towards the development of a field-deployable test for their presence in order to determine marijuana ingestion. Outcomes of this project will lead to the ability to rapidly and non-invasively screen for marijuana use in a variety of circumstances in the fields of forensic science and criminal justice, including driving under the influence of drugs (DUID) cases, airport security, illicit drug use in the military, prison systems, and medical examiner/coroner offices. Semi-annual/final progress and financial reports, as well as scholarly products (e.g., peer-reviewed articles), will be produced. NCA/NCF
