Identification and analytical properties of acetyl fentanyl metabolites

Acetyl fentanyl is a novel designer drug substance, a derivative of fentanyl. Its major metabolites were identified in samples of urine from consumers of acetyl fentanyl using gas chromatography and high-performance liquid chromatography with mass spectrometry detection. Structures of metabolites were proposed and confirmed by their fragmentation on electron impact and atmospheric pressure chemical ionization. The mass spectral and chromatographic properties of some derivatives of acetyl fentanyl metabolites were determined. The main path of the biotransformation of acetyl fentanyl is the hydroxylation of the phenylethyl moiety in the molecule.