Application of ToF-SIMS to detection and imaging of cannabis-contaminated fingerprints – A preliminary study

Humans have used cannabis for centuries for medical and recreational purposes. In some countries, such as the Netherlands, individuals are permitted to possess small amounts of cannabis for personal use, whereas in others, it is only available for medical purposes. However, cannabis is prohibited in the majority of countries and can only be obtained through illicit channels. Therefore, reliable methods for identifying cannabis are necessary in these countries especially with regard to fingerprints, which may contain traces of various substances, including psychoactive substances. This study presents the results of using the ToF-SIMS technique to detect cannabis-related compounds present as contaminants in fingerprints. These include tetrahydrocannabinol (THC), cannabidiol (CBD), cannabivarin (CBV), cannabinol (CBN) and cannabidiolic acid (CBDA). Additionally, the ToF-SIMS technique was tested for its ability to record images of fingerprints contaminated with dried cannabis. This technique makes such research possible and has a variety of applications, including in forensic science. During this study, the volunteers' fingerprints, which had been contaminated with cannabis (marijuana), were revealed using black, antistatic fingerprint powder. They were then transferred using fingerprint tape. The ToF-SIMS technique was found to allow cannabis to be detected in fingerprints transferred with the fingerprint tape. Furthermore, the spatial distribution of cannabis residues on transferred fingerprints could be demonstrated using ToF-SIMS imaging. These preliminary results suggest ToF-SIMS could be a valuable tool for the forensic analysis of cannabis residues on fingerprints.