Performance assessment of portable Raman spectroscopy in determining ecstasy tablets

Ecstasy tablets, a type of common street drug originally consisting of 3,4-methylenedioxymethamphetamine (MDMA), provide stimulant and hallucinogen psychoactive effects. They are frequently found in nightclubs, musical festivals or other recreational events believed to create a relaxing experience for the users. From a forensic perspective, when the drug of abuse is suspected in such scenarios, the law enforcement personnel would then require an easy-to-perform, quick and accurate method to detect the existence of such controlled substance prior to the seizure and subsequent forensic examination. In this study, we assessed the performance of a portable Raman spectroscopy as the primary aid in determining ecstasy tablets at the point of use. A total of 130 ecstasy tablet samples were analysed by Raman spectroscopy and characterised by gas chromatography–mass spectrometry (GC–MS). Active chemical substances and cutting agents detected by the two instrumentations were then compared. The performance of Raman spectroscopy was further assessed in terms of its accuracy, sensitivity and specificity, corresponding to the analysis results obtained from GC–MS analysis. Overall, portable Raman Spectroscopy used in this study shows an accuracy of 85.4% in analysing ecstasy tablets obtained from case samples, while the sensitivity and specificity were determined as 85.2% and 100%, respectively. No false positives for MDMA or other drugs were reported. Our results show that portable Raman spectroscopy is a suitable technique for targeted determination of the presence of ecstasy tablets, especially in forensic cases that require non-destructive, rapid and mass screening during on-site testing by law enforcement personnel.