ANALYSIS OF INORGANIC IMPURITIES IN SEIZED METHAMPHETAMINE SAMPLES

Classification of seized methamphetamine by impurity profiling can pro vide very useful information on drug intelligence. In this report, the validity of inorganic impurity analysis in discriminating seized meth amphetamine samples in Japan was investigated using inductively couple d plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS). Triplicate sampling was carried out on 17 methamphetamine samp les seized in Japan. About 20 mg of methamphetamine was taken, and was dissolved in 20 mi of water. After the qualitative analysis, Ba, Sb, Pd, Sr, Br, Zn and Cu were determined by ICP-MS, and Na was determined by AAS. Among eight elements determined in this study, most cations s howed large heterogeneity in their content. On the other hand, the con tents of Na which is abundant in methamphetamine samples, showed relat ively small intra-sample variation, and that of Br also showed good ho mogeneity. On the basis of the concentration of Br and Na, 17 seized m ethamphetamine samples were classified into five groups. Trace element s such as Tl, Hg, Au or Cs were qualitatively detected by ICP-MS. Thes e elements can provide useful information to impurity profiling of sei zed methamphetamine, because these elements are characteristically pre sent in each sample. Application of ICP-MS and AAS to the analysis of inorganic impurities can be helpful in giving additional information t o the impurity profiling of seized methamphetamine by organic impurity analysis.