Chemical profiling of 3,4-methylenedioxymethamphetamine (MDMA) tablets seized in Hong Kong

During 2000-2001, the Government Laboratory of Hong Kong received over 600,000 ecstasy tablets in more than 2,600 cases. Using GC-MS or FTIR, the major amphetamine-type stimulants were identified, and the samples were categorized into four groups containing: (1) 3,4-methylenedioxymethamphetamine (MDMA), (2) methamphetamine (MA), (3) 3,4-methylenedioxyamphetamine (MDA), or (4) amphetamine. Our study revealed that in Hong Kong MDMA tablets have made up 98 and 71% of the total ecstasy tablets examined in 2000 and 2001, respectively. Among the MDMA cases, 613 cases involving a total of 123,776 tablets in 2001 were randomly selected, and their active ingredients, minor ingredients, and/or impurities were studied using GC-MS and HPLC. Based on the chemical profiles, and irrespective of their different physical characteristics, tablets obtained in different seizures could be determined as to whether or not they could have come from a common origin. The impurities detected in the MDMA tablets also served as excellent chemical markers from which plausible synthetic route(s) of the MDMA were inferred. Our study revealed that 3,4-methylenedioxyphenyl-2-propanone (MDP2P), 3,4-methylenedioxyphenyl-2-propanol (MDP), 3,4-methylenedioxy-N-methylbenzylamine (MDB), piperonal and N-formyl-3,4-methylenedioxymethamphetamine (N-formyl-MDMA) were the most common impurities detected in MDMA tablets seized in Hong Kong. The finding of the phosphate salt of MDMA is intriguing. Based on a presumptive color test, spectroscopic data (FTIR/ESI-MS) and the percentage of MDMA content in a purified phosphate salt of MDMA, the ratio of the phosphate to MDMA was determined to be 1:1, suggesting that the compound is a dihydrogen phosphate salt [i.e. (HMDMA)H2PO4].