Analysis of pharmaceutical impurities in the methamphetamine crystals seized for drug trafficking in Korea

Some methamphetamine (MA) crystals contain pharmaceutical impurities. They often come from the co-ingredients of cold drugs used for extracting ephedrine or pseudoephedrine. Though these impurities are not so commonly encountered, they reflect the trends in precursor chemicals and manufacturing sources. As a result of monitoring impurities in the MA crystals seized in Korea during 2006–2011, 10 species of pharmaceutical impurities were identified by gas chromatography–flame ionization detection and gas chromatography–mass spectrometry. They may be co-ingredients of the legal drugs used as a source of ephedrine or pseudoephedrine. In contrast, some of them are presumed to be adulterants added during or after clandestine synthesis. It is interesting that some of these have been identified in the MA crystals seized in other countries in the same year. Species of pharmaceutical impurities in the MA crystals increased particularly in 2010, indicating a change in precursor chemicals and/or manufacturing sources.