Rapid & Non-Invasive Screening of Cannabis in Human Hair and Nails Using Attenuated Total Reflectance FTIR: A Pilot Study

Cannabis is one of the most commonly abused substances globally. Rapid, non-invasive detection of cannabis use is crucial for screening purposes in forensic and workplace testing. Keratinized matrices like hair and nails serve as good samples for detecting past cannabis use. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy is a fast, cost-effective, non-destructive, and less invasive method for detecting cannabis exposure from hair and nail samples. The primary objective of this study is to validate keratinized matrices as an effective medium for cannabis detection and to assess the detectability and reliability of ATR-FTIR. The study was conducted in Jhansi, India. Hair and nail samples were collected from 16 volunteers and analyzed alongside a standard cannabis reference sample. Distinct absorption peaks characteristic of major cannabinoids, such as tetrahydrocannabinol (THC) and cannabidiol (CBD), were consistently observed in samples from cannabis users, particularly in nail matrices. In contrast, these signals were absent in samples from non-users. These findings demonstrate that ATR-FTIR has the potential to be an effective method for detecting past cannabis use using hair and nails in resource-limited contexts.