Identification and quantification of mepirapim and acetyl fentanyl in authentic human whole blood and urine samples by GC-MS/MS and LC-MS/MS.

We encountered a curious case in which two male subjects self-administered mepirapim plus acetyl fentanyl by different routes, i.e., intravenously and by inhalation. We have thus established a detailed procedure for quantification of mepirapim and acetyl fentanyl in whole blood and urine specimens using gas chromatography (GC)-tandem mass spectrometry (MS/MS).