Assignment of batch membership of 3,4-methylenedioxy methylamphetamine hydrochloride by comparison of organic impurity profiles

- Synthesised 'ecstasy' shows between-batch variation in impurity profiles.
- Correlation between same and different batches allows discrimination.
- Tablets from different batches can also be distinguished.

The illegal drug 3,4-methylenedioxymethylamphetamine, also known as MDMA, ecstasy or 'E', synthesised as the hydrochloride and then made into tablets, has organic impurities arising from manufacture that can be used to profile seized material. Knowing if two samples come from the same batch gives strategic information about the drug manufacturing trade. We report similarity measures (Pearson correlation coefficient, reported as the modified Pearson distance, and its Fisher transform) between impurity content of pairs of samples manufactured using four common reductive amination routes. Powder and tablets are compared using the nth root of GC-MS peak normalised areas of 8 or 31 impurities, (n = 2, 3, 4, 5, 10). Overall using 31 compounds with 4th root pre-treatment gave the best discrimination. PtO2/H2, and Al/Hg reductions were completely discriminated among batches while NaBH4 and NaBH3CN routes gave around 4% false assignments. Synthesis parameters were systematically altered to determine what parameters have significant effects on the overall purity of the product and on the impurity profiles. The amount ratio of methylamine and MDP2P, and the temperature control of the reaction mixture were both significant. Comparison of modified Pearson's distances (r scaled to ∈[0-100]), the Fisher transform of r, and ROC curves are simple ways of providing initial evidence whether seized drugs originate from the same batch.