Identification of IY81149 and its metabolites in the rat plasma using the on-line HPLC/ESI mass spectrometry

Reversed-phase high-performance liquid chromatography/mass spectrometry (HP LC/MS) with an electrospray ionization (ESI) interface was applied to the i dentification of metabolites of IY 81149 in the rat plasma. Fragments obtai ned using collision-induced dissociation (CID) in both positive and negativ e modes were utilized to elucidate the structure of metabolites. The eluent from the conventional HPLC column was split and directly introduced into a n ESI-mass spectrometer for the identification of the structures. The CID t echnique allowed the sensitive identification of sulfonyl-IY81149 and hydro xy-IY81149 from the rat plasma.