Analysis of Impurities in Methamphetamine

Abstract

Impurities in methamphetamine (MA) synthesized from ephedrine were identified by thin-layer chromatography, gas liquid chromatography, infrared spectroscopy, ultraviolet spectroscopy, proton magnetic resonance spectroscopy, gas chromatography/mass spectrometry and neutron activation analysis. Benzyl methyl ketone and iodine were detected as impurities in MA prepared by reducing ephedrine with hydrogen iodide and red phosphorus. Ephedrine, 1-phenyl-2-methylamino-1-propanone, palladium and barium were detected as impurities in MA prepared by reducing ephedrine with hydrogen and Pd-BaSO₄. Ephedrine, 1, 2-dimethyl-3-phenyl aziridine, palladium and barium were detected as impurities in MA prepared by reducing chloroephedrine with hydrogen and Pd-BaSO₄. Knowledge of impurities contained in MA provides important information regarding synthetic methods. Impurities contained in seized MA were analyzed by the method described above, and synthetic methods were assumed.