A Dried Spot Liquid Chromatography Method to Measure 3,4-Methylenedioxymethamphetamine and 3,4-Methylenedioxyamphetamine in Oral Fluid
Forensic Sciences – January 26, 2026
Source: OpenAlex
Summary
Dried Oral Fluid Spots (DOFS) provide a stable and cost-effective method for detecting MDMA and MDA in oral fluid, crucial for forensic toxicology. Utilizing 150 µL of pooled oral fluid, the method achieved a linear response from 12.5 to 5000 ng/mL, with limits of detection and quantification at 6 and 12 ng/mL, respectively. Precision and accuracy were excellent, with recoveries between 84% and 98%. This DOFS-based workflow enhances flexibility and applicability in various forensic laboratory settings, ensuring reliable drug 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.