The one-step breakdown and derivatization of a panel of nine fentanyls to yield uniquely tagged products that can be detected by Electron Ionization Gas Chromatography-Mass Spectrometry (EI-GC-MS) is presented. The method involves the treatment of the synthetic
opioids with 2,2,2-trichloroethoxycarbonyl
chloride (TrocCl) at 60 °C for 3 h in
dichloromethane and furnishes two products from one
fentanyl molecule that can be used to retrospectively identify the original
opioid. Parameters that were studied and fully optimized for the method included temperature,
solvent, nature of scavenging base and reaction time. One of the two resulting products from the reaction bears the trichloroethoxycarbonyl (Troc) tag attached to the
norfentanyl portion of the original
opioid and greatly
aids in the
opioid detection and identification process. The methodology has been applied to the chemical modification of a panel of nine fentanyls and in all cases the molecular ion peak for the Troc-
norfentanyl product bearing the distinctive trichloroethyl isotopic signature can be clearly observed. The method's LLOD was determined to be 10 ng/mL while its LLOQ was found to be 20 ng/mL. This methodology represents the first application of chloroformates in the chemical modification of this class of synthetic
opioids that are notoriously inert to common derivatization strategies available for GC-MS analysis.