Furanylfentanyl in whole blood measured by GC-MS/MS after QuEChERS extraction in a fatal case

Purpose The purpose of this work is the determination of the probable cause of a person's death on the basis of analytical results obtained from the deceased's blood sample. Methods To establish the concentration of furanylfentanyl (Fu-F) in whole blood samples, QuEChERS extraction coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS) was applied. Results The following QuEChERS parameters have been established as optimal for Fu-F analysis: NaCl 80 mg; MgSO(4)150 mg; acetonitrile 650 mu L, and C-18 sorbents 12.5 mg for a 350 mg blood sample. The following validation parameters characterized the analytical utility of the described method: linearity (R-2 = 0.9975), limit of detection = 0.42 ng/mL and limit of quantification = 1.39 ng/mL, and satisfactory inter- and intraday precisions (% relative standard deviation <= 5.73). The postmortem analysis of whole blood samples disclosed a high concentration of Fu-F at 11.2 ng/mL. Conclusions The present paper describes a fatal case of Fu-F overdose. The described analytical method involving QuEChERS sample preparation procedure followed by multiple reaction monitoring of GC-MS/MS was very convenient to find the presence of Fu-F in postmortem whole blood samples and to establish its concentration. The known circumstances of death in combination with the obtained analytical data indicated that the deceased young male probably got fatally poisoned by Fu-F. The high concentration of Fu-F (11.2 ng/mL) in his postmortem whole blood sample was several times higher than that described in the forensic literature. In our knowledge, this is the first trial to analyze Fu-F by GC-MS/MS.