The Drug Information and Monitoring System (DIMS) in the Netherlands provides drug checking services where individuals can submit samples for analysis and receive tailored harm reduction advice. Ecstasy tablets represent nearly half of all submissions, with over 18,000 substances analyzed in 2024. This demand places high pressure on laboratory capacity, which traditionally relies on GC-MS and LC-DAD. The sample composition is usually reported back one week later, accompanied by harm reduction advice to mitigate health risks.
To address this need, a portable near-infrared (NIR) spectrometer—the Powder Puck—was developed for rapid, on-site analysis. In this study, 120 ecstasy tablets were analyzed using a combined NIR–NMR workflow. Each tablet was milled, and ~10 mg aliquots were first measured by NIR and then subjected to nuclear magnetic resonance (NMR) spectroscopy. Maleic acid served as an internal standard and deuterium oxide as a solvent for quantitative NMR. Collecting both spectra from the same material enabled direct calibration of NIR chemometric models with high-quality reference data.
The workflow achieved 95% sensitivity and 100% specificity, missing only six tablets with very low MDMA content (<10 wt%) or high adulterant levels. NIR predictions calibrated with NMR yielded a root mean squared error of prediction (RMSEP) of 5 wt%, comparable to laboratory methods and within accepted sampling error.
By combining the speed of portable NIR with the accuracy of NMR calibration, analysis time can be reduced from about one week to under one minute. Using NMR as a reference allowed more accurate dose calibration, particularly for tablets with low or high MDMA content, and highlighted areas for improving chemometric models. This study demonstrates the potential of NIR–NMR methodologies to provide rapid, reliable, and field-deployable identification and quantification of MDMA, strengthening harm reduction services through real-time drug content reporting.
