Mass spectrometric identification and structural analysis of the third-generation synthetic cannabinoids on the UK market since the 2013 legislative ban

Abstract

To examine the impact of the second legal ban on synthetic cannabinoids (SCs) in the UK in February 2013, we surveyed the UK legal high market just before and after the change in legislation, looking for new SCs. The technique gas chromatography–mass spectrometry (GC–MS) in electron ionization mode, most widely applied for analysis, was found to be insufficient for the identification of several SCs, and therefore liquid chromatography–high-resolution mass spectrometry (LC–HR-MS) was required. LC–HR-MS(/MS) measurements of the protonated molecules and product ions allowed the detection of up to 27 compounds as the third-generation SCs in the samples analysed as part of this study, including two unknown compounds that were tentatively identified as F2201 and dealkyl-SDB-006. Our results showed that banned compounds were removed from the market on the day when the ban was in place, and were replaced by other SCs immediately after the ban. In only one occasion, a banned compound (UR-144) was detected after the date when the new legislation came into place. It is also noteworthy that regardless of the change in legislation, new compounds continued to enter the market. Product ion spectral information on the third-generation SCs at different collision energies given in this paper will be of help for forensic and clinical laboratories and will facilitate the detection and identification of new SCs by laboratories of control. This information is very valuable for law enforcement and policymakers and will be of help in future prevention programs.