Analysis of pyrolysis products of dimethylamphetamine.

This study examines the pyrolysis products of dimethylamphetamine (DMAMP) and its pyrolysis mechanism. A sealed glass tube, in which DMAMP-HCI was placed, was wrapped with pyrolysis-foil and heated at the Curie point of the pyrolysis-foil. The pyrolysis products of DMAMP were detected by gas chromatography-mass spectrometry (GC-MS), headspace (HS)-GC-MS and liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). DMAMP-d6-HCl, in which all the hydrogen atoms of the two methyl groups of DMAMP were substituted with deuterium atoms, was pyrolyzed to investigate the elimination and transformation reactions of the methyl group. Methamphetamine (MAMP) and amphetamine (AMP) were produced via demethylation reaction by heating DMAMP, and the maximum amounts of MAMP and AMP were about 31.8% and 13.7% of the starting DMAMP at 358 degrees C and 386 degrees C, respectively. The reactions of a chlorine anion and DMAMP with a methyl group eliminated from the dimethylamino group of DMAMP resulted in the formation of methyl chloride and benzylethyltrimethylammonium, respectively. These results indicate that one of the demethylation and methylation reactions occurs in the form of a methyl cation.