The potential of IR absorption and Raman spectroscopy for rapid identification of novel psychoactive substances (NPS) has been tested using a set of 221 unsorted seized samples suspected of containing NPS. Both IR and Raman spectra showed large variation between the different sub-classifications of NPS and smaller, but still distinguishable, differences between closely related compounds within the same class. In initial tests, screening the samples using spectral searching against a limited reference library allowed only 41% of the samples to be fully identified. The limiting factor in the identification was the large number of active compounds in the seized samples for which no reference vibrational data were available in the libraries rather than poor spectral quality. Therefore, when 33 of these compounds were independently identified by NMR and mass spectrometry and their spectra used to extend the libraries, the percentage of samples identified by IR and Raman screening alone increased to 76%, with only 7% of samples having no identifiable constituents. This study, which is the largest of its type ever carried out, therefore demonstrates that this approach of detecting non-matching samples and then identifying them using standard analytical methods has considerable potential in NPS screening since it allows rapid identification of the constituents of the majority of street quality samples. Only one complete feedback cycle was carried out in this study but there is clearly the potential to carry out continuous identification/updating when this system is used in operational settings.

A set of seized “legal high” samples and pure novel psychoactive substances have been examined by surface-enhanced Raman spectroscopy using polymer-stabilized Ag nanoparticle (Poly-SERS) films.

The racemic tertiary cathinones N,N-dimethylcathinone (1), N,N-diethylcathinone (2) and 2-(1-pyrrolidinyl)-propiophenone (3) have been prepared in reasonable yield and characterized using NMR and mass spectroscopy. HPLC indicates that these compounds are isolated as the anticipated racemic mixture. These can then be co-crystallized with (+)-O,O′-di-p-toluoyl-D-tartaric, (+)-O,O′-dibenzoyl-D-tartaric and (−)-O,O′-dibenzoyl-L-tartaric acids giving the single enantiomers S and R respectively of 1, 2 and 3, in the presence of sodium hydroxide through a dynamic kinetic resolution. X-ray structural determination confirmed the enantioselectivity. The free amines could be obtained following basification and extraction. In methanol these are reasonably stable for the period of several hours, and their identity was confirmed by HPLC and CD spectroscopy.