Assessing the suitability of ‘mass loss analysis’ as a low cost, low technology test to approximate MDMA content in ecstasy tablets, using laboratory and field comparisons
Research Square November 5, 2025 preprint DOI: 10.21203/rs.3.rs-7670422/v1 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Laboratory and field method-comparison study |
|---|---|
| Sample size | 13 |
| Population | Ecstasy tablets tested in a laboratory and in a temporary field laboratory |
| Measures | quantitative nuclear magnetic resonance (qNMR) spectroscopy, Bland–Altman approach |
| Topics | MDMA |
| Key points | MLA showed reasonable agreement with qNMR for semi-quantifying MDMA in ecstasy tablets, though it overestimated content by an average of 14 mg per tablet, with accuracy improving as MDMA content increased. Field comparisons with other drug-testing organisations also showed reasonable agreement on average tablet strength. The authors conclude MLA is accurate and precise enough for temporary laboratories when used alongside other analytical techniques. |
Abstract
Abstract Background MDMA-related deaths increased by over 50% year on year in the most recent official statistics for England and Wales, despite prevalence of use being at its lowest level on record. Identifying the content and strength of ecstasy tablets enables public health and harm reduction services to better monitor unregulated drug markets and disseminate information about substances of concern in circulation, including high and variable strength tablets. Developing an easily transportable, low cost, low technology test to approximate strength, for use within event-based temporary laboratories, can assist onsite support services through time and location-specific information.
Methods: The accuracy and utility of a solvent extraction-based procedure (mass loss analysis; MLA) to semi-quantify ecstasy tablets was assessed in laboratory and field settings. Firstly, a laboratory study compared MLA with quantitative nuclear magnetic resonance (qNMR) spectroscopy for 13 ecstasy tablets. Precision was determined through repeat measures of pooled batches and methodological agreement was determined using the Bland–Altman approach. Secondly, comparisons were made between tablets tested in a temporary field laboratory using MLA and data from European drug testing organisations using other analytical techniques.
Results: Laboratory comparison found reasonable agreement between MLA and qNMR measurements, with MLA overestimating content by an average of 14 mg/tablet, with accuracy increasing with MDMA content. Comparison between MLA test results and other drug testing organisations also found reasonable agreement on average tablet strength.
Conclusions: These findings suggest that the accuracy and precision of MLA is sufficient to support its utility in temporary laboratories when triangulated with other analytical techniques. As the cost of equipment and consumables is modest, the approach is well suited for organisations operating on limited budgets. Therefore MLA offers the potential to widen access to, and effective use of, semi-quantitative information on ecstasy tablets which pose increased risk, particularly in the context of the current UK market, with high and variable strength tablets of low cost and little adulteration or mis-selling. Such information can support harm reduction messaging, with the aim of reducing risk of overdose, against a backdrop of significantly increased MDMA-related deaths proportionate to prevalence of use in the UK.