Structural modification of fentanyls for their retrospective identification by gas chromatographic analysis using chloroformate chemistry.

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.

The crystal structure of bis-{3,5-di-fluoro-2-[4-(2,4,6-tri-methyl-phen-yl)pyridin-2-yl]phen-yl}(picolinato)iridium(III) and its 4-tert-butyl-pyridin-2-yl analogue.

The crystal structures of bis-{3,5-di-fluoro-2-[4-(2,4,6-tri-methyl-phen-yl)pyridin-2-yl]phenyl-κ2 N,C 1}(picolinato-κ2 N,O)iridium(III), [Ir(C20H16F2N)2(C6H4NO2)], 1, and bis-[2-(4-tert-butyl-pyridin-2-yl)-3,5-di-fluoro-phenyl-κ2 N,C 1](picolinato-κ2 N,O)iridium(III), [Ir(C15H14F2N)2(C6H4NO2)], 2, are presented herein. These phospho-rescent cyclo-metallated iridium(III) compounds have been structurally investigated in order to better understand the nature of their blue-shifted emssions while maintaining high quantum yields. Compound 1 exhibits substantial twisting of the mesitylene rings out of the plane of the attached pyridine ring, with dihedral angles of 67.0 (1) and 78.7 (1)° between the best mean planes. For both compounds, the contribution of disordered solvent mol-ecule(s) was removed using the SQUEEZE [Spek (2015 ▸). Acta Cryst. C71, 9-18] routine in PLATON [Spek (2015 ▸). Acta Cryst. C71, 9-18]. These solvent mol-ecules are not considered in the given chemical formula and other crystal data.