Fast & fluorinated – Development and validation of a rapid benchtop NMR approach and other routine screening methods for the detection and quantification of synthesized fluorofentanyl derivatives

Fluorinated fentanyl regioisomers have become increasingly common in forensic casework. This study reports the synthesis of eight fluorinated derivatives as pure reference materials and their complete NMR, infrared mass spectral characterisation. Presumptive colour tests TLC results are presented an initial screening method for these compounds. The fully validated GC–MS (employing SIM mode) allows quantification target analytes (LOD = 9–20 ng/mL, LOQ 31–67 ng/mL), fentanyl, heroin, acetaminophen caffeine, within 13 min. In most cases, regioisomeric fluorofentanyls were resolved from each other except 3?- 4?-fluorinated (5b 5c). To achieve full separation, orthogonal benchtop 19F NMR identification analogues 74–400 ?g/mL, 290–1340 ?g/mL). detection at a low concentration (2.4% w/w) heroin.