Prevalence and co-existence of active components of 'legal highs'.

The results of a study performed on samples of 'legal highs' seized in head shops by law enforcement and health services in Poland between mid-2008 and mid-2011 are presented. In total, 449 preparations which differed in labelling, net masses, forms of distribution, etc., were analyzed. A variety of sophisticated analytical methods, including gas chromatography-mass spectrometry (GC-MS), liquid chromatography-quadropole time-of-flight mass spectrometry (LC-QTOF-MS), high performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) were applied for component identification and quantification. The most common ingredients of legal highs were (in descending order): MPDV, caffeine, butylone, TFMPP, lidocaine, 4-MEC, mephedrone, pFPP, BZP, and MDPBP. The scatter of substances changed over time, and piperazines were often ousted by cathinones. Most of the preparations were composed of two or more ingredients. Cathinones and piperazines were mixed mainly within the chemical classes (77.6% and 56.1% of dual links, respectively), caffeine was mixed both with piperazines (24 products) and cathinones (22 products), whereas lidocaine only with the latter class (47 products). A great inconsistency in the qualitative and quantitative composition of products with identical labelling was shown in an example of Coco products seized after August 2010; we found 10 different single component or mixture preparations, and the content of individual ingredients varied from several to hundreds of mgs. This paper summarizes potential dangers connected with the uncontrolled sale of psychoactive substances, and indicates important issues concerning the analysis of legal highs.