Abstract: The purpose of this stUdy is to investigate themetabolism of MDMA in the person and establish themethods for the determination of MDMA and itSmetabolites in urine. MDMA and itS metabolite wereisolated from urine by liquid-liquid extraction afteracidic or enzymatic hydrolysis and were determined byGC/MS(EI、 PCI) and GC/FID. The results showed thatMDMA was metabolized to MDA and HMMA in man.MDA in the urine after MDMA administration wasapproximately 0.10-0.14 that of the parent drug. Thesensitivity limits of methods were 2-50 ng/ml, and therecoveries were greater than 85%(CV<10%). It isconcluded that the methods were simple, quick andaccurate for determining urine concentration of MDMAaddicts. MDA/MDMA Ratio can be used to indicatewhether the parent drug is taken alone or in combinationwith itS active metabolite.Keywrds: MDMA; metabolites; metabolite to parentratio

Key words: MDMA, metabolites, metabolite to parent ratio