Australian Federal Police seizures of illicit crystalline methamphetamine ('ice') 1998-2002: impurity analysis

Nineteen crystalline methamphetamine ('ice') seizures captured by the Australian Federal Police (AFP) at the Australian border between 1998 and 2002 were analysed. Using a modified gas chromatograph-mass spectrometry (GC-MS) impurity profiling approach of these samples we have identified >30 compounds associated with methamphetamine and/or its synthetic route. Major impurities detected include 1,2-dimethyl-3-phenylaziridine 8, dimethylamphetamine 14, N-formylmethamphetamine 24, N-acetylmethamphetamine 25, 1,3-dimethyl-2-phenylnaphthalene 32, 1-benzyl-3-methylnaphthalene 33 and methamphetamine dimer 34. These data are suggestive of ephedrine/pseudoephedrine as the main precursor of the 'ice' samples seized during 1998-2002. Additionally the two naphthalenes 32 and 33 further identified that 15 items in 9 seizures were produced via the more specific ephedrine/hydriodic acid/red phosphorus method. One sample comprised 75% dimethylamphetamine and 9.7% methamphetamine, representing the first Australian seizure of imported dimethylamphetamine reported.