Separation and identification of corticosterone metabolites by liquid chromatography electrospray ionization mass spectrometry

High-performance liquid chromatography coupled to atmospheric pressure ioni zation-electrospray ionization mass spectrometry (API-ESI-MS) was investiga ted for the analysis of corticosterone metabolites; their characterization was obtained by combining the separation on Zorbax Eclipse XDB C-18 column (eluted with a methanol-water-acetic acid gradient) with identification usi ng positive ion mode API-ESI-MS and selected ion analysis. The applicabilit y of this method was verified by monitoring the activity of steroid convert ing enzymes (20 beta-hydroxysteroid dehydrogenase and 11 beta-hydroxysteroi d dehydrogenase) in avian intestines. (C) 1999 Elsevier Science B.V. All ri ghts reserved.