Analysis of Fragmentation Pathways of New-Generation Synthetic Cannabinoids (INACA, IATA, FUPPYCA, and OXIZID Type Compounds) Based on Electrospray Ionization High-Resolution Mass Spectrometry

A rapid introduction of new psychoactive substances onto the illicit drug market and the dynamic changes in their structures cause the identification of novel compounds to be difficult and time-consuming. This is related to the possible lack of mass spectra of new substances in spectral libraries or the unavailability of certified reference materials. Therefore, this study analyzed the fragmentation patterns of 24 synthetic cannabinoids recently reported to the European Early Warning System. The tested compounds were divided into subgroups based on similarity of core structure and linker moiety, i.e., the synthetic cannabinoids with the acronym INACA (containing an indazole core and a carboxamide linker), the IATA compounds with an indole core and an acetamide linker, the FUPPYCA synthetic cannabinoids (containing a 4-fluorophenyl-pyrazole core and a carboxamide linker), and the OXIZID compounds which are characterized by a 2-oxindole core and a hydrazide linker. The analysis was carried out by quadrupole time-of-flight mass spectrometry with electrospray ionization (ESI-QTOFMS). High mass accuracy of the applied technique allowed us to determine the preferred fragmentation routes of novel synthetic cannabinoids. The main cleavage for the compounds with the acronyms INACA, IATA, and FUPPYCA occurred on the bond adjacent to the carbonyl group constituting part of the molecule linker. Instead, for the OXIZID type group, neither ions originating from the core of the molecule nor ions from the linker and tail were observed. Knowledge of the characteristic ions of compounds from a certain chemical group can be helpful in the elucidation of the structure of new substances that may appear in products seized on the drug market.