Abstract:
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. 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. 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.
Referência:
OKA-DUARTE, Leandro; FERREIRA, Bruno; OLIVEIRA, Marcelo Firmino de. A dried spot liquid chromatography method to measure 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxymphetamine in oral fluid. Forensic Science, v.6, n.1, 1-16, 2026.
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