Investigation into the Analysis of Fentanyl in Postmortem Blood using Biocompatible Solid-Phase Microextraction

Over recent years, the abuse of fentanyl and other opioids has become a slow motion mass disaster in the United States resulting in an increased number of drug-related deaths. Various postmortem biological samples are collected by forensic pathologists during autopsy and then sent to a toxicology laboratory to be analyzed for the presence of various compounds such as fentanyl. This process can be time consuming and results in a backlog, potentially hindering an investigation. A possible solution is Biocompatible Solid-Phase MicroExtraction (BioSPME) fibers. These fibers can be directly inserted into a biological matrix and absorb drug compounds without the interference of macromolecules that may be present allowing for a faster analysis time. An initial method has been developed to analyze fentanyl in postmortem blood using BioSPME followed by GC-MS and LC-MS-MS analysis. BioSPME fibers were conditioned, washed, directly inserted into postmortem blood, washed, filtered, desorbed into solution, dried down and reconstituted. The extracted samples were screened by GC-MS and subsequently analyzed by LC-MS-MS. GC-MS was performed using splitless injection on a Rxi-5Sil MS column (30.0 m × 0.25 mm, 0.25 μm) in the SIM mode. Samples were confirmed using an AB SCIEX™ 3200 QTRAP® triple quadrupole mass spectrometer with ElectroSpray Ionization (ESI) source in the positive ion mode. Liquid Chromatography was performed on a Shimadzu® LC system using an Ascentis® Express Biphenyl column (50 mm × 2.1 mm, 2.7 μm) with the weak mobile phase of 0.1%(v/v) formic acid in water and the strong mobile phase of 0.1%(v/v) formic acid in acetonitrile for an analysis time of seven min per sample. This method was developed using bovine blood and then applied to 43 postmortem blood samples provided by the Lehigh County Coroner’s Office (Allentown, PA, USA).