Multi-analytical characterization of 4-fluoro-furanyl fentanyl in a drug seizure

In recent years, the synthesis and introduction of Novel Psychoactive Substances (NPS) into the illicit market has reached alarming levels. More than 730 compounds have been identified by the European Monitoring Center for Drugs and Drug Addiction (EMCDDA). Among the newest NPS, synthetic opioids deserve special attention, in particular fentanyl and its analogues that in 2018 covered more than 70% of the world demand for opioids, with thousands of fatal events in USA. In this context it is of significant importance to have the right tools to identify the most recent NPS exploiting the synergy between different analytical techniques. Two synthetic opioids, belonging to the family of fentanyl derivatives were found in the same seizure occurred in Italy in 2019. IsobutyrylFentanyl (iBF) and 4-Fluoro-Furanylfentanyl (4F-FuF) were identified. A comprehensive elucidation of 4F-FuF by means of several analytical techniques, namely IR, Raman, GC-MS, LC-HRMS/MS and NMR, is provided in this work. In Italy, as a result of the present study, a formal notification of 4F-FuF to the national early warning system was sent and notification to EMCDDA ensued.