A Dried Spot Liquid Chromatography Method to Measure 3,4-Methylenedioxymethamphetamine and 3,4-Methylenedioxyamphetamine in Oral Fluid
Forensic Sciences January 26, 2026 Leandro Oka-Duarte, Bruno Ferreira, Marcelo Firmino de Oliveira
A new method using dried oral fluid spots (DOFS) on watercolor paper pretreated with diluted nitric acid can reliably measure the stimulant drugs MDMA and MDA. The method uses liquid chromatography with a diode-array detector and shows linear results across a wide concentration range (12.5 to 5000 ng mL−1), with detection limits as low as 6 ng mL−1. Recoveries of the drugs from the dried spots ranged from 84% to 98%, and the samples remained stable under various storage conditions. This approach offers a low-cost, practical alternative to liquid oral fluid for forensic drug testing, especially in settings where refrigeration is difficult.