Ultraviolet-Visible and High-Resolution Mass Spectrometry for the Identification of Cyclopropyl-Fentanyl in the First Fatal Case in Spain.

Here we report the identification and quantitation of cyclopropyl-fentanyl in a fatality casework occurred due to a poly-drug toxicity in Spain in December 2017. The cyclopropyl-fentanyl was identified in non-biological (paraphernalia) and biological samples (whole-blood, vitreous humor and urine). Conventional techniques (GC-MS) and the UV-Vis spectral allowed differencing between the two structural isomer compounds of fentanyl (cyclopropyl and crotonyl) when the CRM was not available at the laboratory.