Postmortem tissue distribution of acetyl fentanyl, fentanyl and their respective nor-metabolites analyzed by ultrahigh performance liquid chromatography with tandem mass spectrometry

Abstract

In the last two years, an epidemic of fatal narcotic overdose cases has occurred in the Tampa area of Florida. Fourteen of these deaths involved fentanyl and/or the new designer drug, acetyl fentanyl. Victim demographics, case histories, toxicology findings and causes and manners of death, as well as, disposition of fentanyl derivatives and their nor-metabolites in postmortem heart blood, peripheral blood, bile, brain, liver, urine and vitreous humor are presented. In the cases involving only acetyl fentanyl (without fentanyl, n=4), the average peripheral blood acetyl fentanyl concentration was 0.467mg/L (range 0.31 to 0.60mg/L) and average acetyl norfentanyl concentration was 0.053mg/L (range 0.002 to 0.086mg/L). In the cases involving fentanyl (without acetyl fentanyl, n=7), the average peripheral blood fentanyl concentration was 0.012mg/L (range 0.004 to 0.027mg/L) and average norfentanyl blood concentration was 0.001mg/L (range 0.0002 to 0.003mg/L). In the cases involving both acetyl fentanyl and fentanyl (n=3), the average peripheral blood acetyl fentanyl concentration was 0.008mg/L (range 0.006 to 0.012mg/L), the average peripheral blood acetyl norfentanyl concentration was 0.001mg/L (range 0.001 to 0.002mg/L), the average peripheral blood fentanyl concentration was 0.018mg/L (range 0.015 to 0.021mg/L) and the average peripheral blood norfentanyl concentration was 0.002mg/L (range 0.001mg/L to 0.003mg/L). Based on the toxicology results, it is evident that when fentanyl and/or acetyl fentanyl were present, they contributed to the cause of death. A novel ultrahigh performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) method to identify and quantify acetyl fentanyl, acetyl norfentanyl, fentanyl and norfentanyl in postmortem fluids and tissues is also presented.