A Dried Spot Liquid Chromatography Method to Measure 3,4-Methylenedioxymethamphetamine and 3,4-Methylenedioxyamphetamine in Oral Fluid
Leandro Oka-Duarte, Bruno Ferreira, Marcelo Firmino de Oliveira
Forensic Sciences January 26, 2026 DOI: 10.3390/forensicsci6010009 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Method development and validation study Peer reviewed |
|---|---|
| Topics | MDMA |
| Keywords | Analyte Matrix chemical analysis High-performance liquid chromatography Accuracy and precision Aqueous solution |
| Key points | A dried oral fluid spot method using watercolor paper pretreated with nitric acid can accurately and precisely quantify MDMA and MDA with good recovery and stability, offering a practical alternative to liquid oral fluid for forensic analysis. |
Abstract
Background/Objectives: MDMA and MDA are among the stimulant drugs most frequently encountered in forensic casework, and oral fluid represents a practical biological matrix for their detection. However, liquid oral fluid requires refrigeration, is susceptible to degradation, and can be logistically demanding for routine laboratories. Dried Oral Fluid Spots (DOFS) offer a low-cost and stable alternative. This study aimed to develop and validate a DOFS-based analytical workflow for quantifying MDMA and MDA using liquid chromatography and a diode-array detector.
Methods: Watercolor paper was selected as the substrate and pretreated with diluted nitric acid to improve analyte desorption. DOFS were prepared using 150 µL of pooled oral fluid, dried for 4 h, and extracted with methanol. Chromatographic separation was performed on a phenyl column using aqueous TFA and acetonitrile mobile phase. Method validation followed the ICH M10 criteria.
Results: The method showed linear responses between 12.5 and 5000 ng mL−1, with LOD and LLOQ of 6 and 12 ng mL−1 for both analytes, respectively. Precision and accuracy met acceptance criteria across all QC levels. Recoveries ranged from 84% to98%. DOFS samples demonstrated adequate stability under multiple storage and handling conditions.
Conclusions: The optimized DOFS–LC–DAD workflow offers a robust, low-cost, and flexible approach for the analysis of MDMA and MDA in oral fluid for laboratory-based or semi-controlled collection environments. Its compatibility with both LC- and GC-based detectors enhances applicability in diverse forensic laboratory settings.