Abuse of recreational drugs (i.e., synthetic chemicals with the structure or expected neurotropic effects, or both, similar to those of controlled substances) is a serious and continuous social harm. Designer drugs are often manufactured or synthesized in small-scale clandestine laboratories with impure starting materials, poor handling skills and inferior storage conditions. Therefore, in addition to the objective compound, diverse impurities may be present, for example, from the starting material, intermediates, catalytic metals formed during chemical synthesis, and materials from the environment. Impurity profiling of drug seizures is a useful scientific tool to obtain information on the clandestine manufacturers and drug trafficking networks. 1-Phenyl-2-(1-pyrrolidinyl)-1-pentanone (α-PVP), a novel psychoactive substance of the cathinone type that is banned in many countries, is still supplied and distributed within the illicit drug market. By using GC-MS and ICP-MS, we identified and estimated the relative contents of organic and inorganic impurities in the bulk powder of 15 batches of α-PVP. We then conducted multivariate data analyses to reveal characteristic patterns of the profiles. Hierarchical cluster analysis of both the organic and inorganic impurities revealed two groups that showed similar impurity profiles, which suggested that the batches in these groups were synthesized in similar routes under similar synthetic environments. The initial groups revealed by the organic impurities were further divided when combined with the data from the inorganic impurities. The present study, therefore, demonstrated the effectiveness of integrated analyses of organic and inorganic impurities for the accurate clustering of designer drugs, to provide precise information to drug investigation authorities.
Keywords: 1-Phenyl-2-(1-pyrrolidinyl)-1-pentanone (α-PVP); GC-MS; Hierarchical cluster analysis (HCA); ICP-MS; Principal component analysis (PCA).