An improved chiral LC-MS/MS method separates all four pairs of enantiomers of MDMA and its major phase-1 metabolites (HMA, HMMA, MDA) on a single Lux AMP column within six minutes, using an optimized mobile phase and column dimensions. The method was applied to human plasma, oral fluid, and urine. In urine, hydrolysis of glucuronides with hydrochloric acid or glucuronidase was tested to evaluate effects on the concentration and enantiomeric distribution of the hydroxy metabolites HMA and HMMA.
MDMA (Ecstasy) is broken down and cleared from the body at different rates for its two mirror-image forms. In oral fluid from 161 samples, the S-(+)-enantiomer of MDMA was eliminated faster (half-life 3.3 hours) than the R-(-)-enantiomer (half-life 4.8 hours). Both reached peak levels within 1.75 hours after taking the drug. For the metabolite MDA, the second enantiomer cleared more quickly (half-life 9.6 hours) than the first (23.8 hours). The ratio of R to S MDMA increased over time, which could help estimate when the drug was taken. In roadside checks, 54.5% of cases had an R/S ratio above 1.5, suggesting use within the prior 24 hours.