Identification of fentanyl metabolites in rat urine by gas chromatography-mass spectrometry with stable-isotope tracers
Goromaru, T.; Matsuura, H.; Furuta, T.; Baba, S.; Yoshimura, N.; Miyawaki, T.; Sameshima, T.
Drug Metabolism and Disposition the Biological Fate of Chemicals 10(5): 542-546
1982
ISSN/ISBN: 0090-9556 PMID: 6128207 Document Number: 186284
The metabolites of fentanyl (l), which has been widely used as a neuroleptic analgesic agent, were identified in urine of rats by gas chromatography-mass spectrometry combined with a stable-isotope tracer technique. After the oral administration of an equimolar mixture of l and deuterium-labeled l (l/l-d5), the urinary metabolites were extracted with chloroform at pH 9.0. Extracts were derivatized and analyzed by GC/MS. Metabolites were identified by the presence of doublet ion peaks separated by 5 amu, and chemical structures were established from analyses of fragmentation pathways. The metabolites were identified as 4-N-(N-propionylanilino)-piperidine, 4-N-(N-hydroxypropionylanilino)piperidine, 4-N-(N-propionylanilino) hydroxypiperidine, 1-(2-phenethyl)-4-N-(N-hydroxypropionylanilino)piperidine and 1-(2-phenethyl)-4-N-(N-propionylanilino)hydroxypiperidine. These metabolites, together with unchanged l, were also detected in urine of rats receiving l/l-d5 intravenously, by selected-ion monitoring of the specific cluster ions.