LAUSR

PurposeImpurity profiling is an important intelligence-gathering tool that can be used to link batches of drugs, and it provides valuable insights into manufacturing and supply trends in new psychoactive substances. In a routine analysis, we detected trace amounts of pyrovalerone in illicit drug products. In this study, we investigated the cause of pyrovalerone’s presence in the illicit drug products containing 4′-methyl-α-pyrrolidinohexanophenone (MPHP) or 4-methyl-α-ethylaminopentiophenone (4-methyl-α-EAPP).MethodsWe analyzed the compounds in illicit drug products and raw material using liquid chromatography–photodiode array detection, gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry.ResultsWe detected trace amounts of pyrovalerone in four illicit drug products containing MPHP or 4-methyl-α-EAPP. In every case, the amount of pyrovalerone in the illicit drug products was much lower than that of MPHP or 4-methyl-α-EAPP. We assumed that pyrovalerone was produced unintentionally. Structurally, pyrovalerone differs from MPHP with respect to the length of the alkyl side chain, and for 4-methyl-α-EAPP, the amine at the α-position is different (it bears an ethylamine instead of pyrrolidine). Pyrovalerone is thought to be produced in two different ways, as a synthetic by-product of both MPHP and 4-methyl-α-EAPP.ConclusionsWe assumed that pyrovalerone was derived from an impurity in a raw material or arose from contamination during the amination process. Impurity analysis, such as that described in this study, will aid in impurity profiling of cathinones.