Mass directed peak selection, an efficient method of drug metabolite identification using directly coupled liquid chromatography-mass spectrometry-nuclear magnetic resonance spectroscopy

Mass spectrometry (both MS and MS-MS) has been used to determine which elut ing chromatography peaks in an LC-MS-nuclear magnetic resonance (NMR) exper iment should be selected for extended NMR spectroscopic measurement. This m ass directed selection of chromatographic peaks has been applied to test mi xtures and urine samples for identification of drug metabolites, It was use d to simultaneously determine when drug-related material was eluting and pr ovided molecular mass information on these components. Stop-flow LC-NMR was used to acquire data for structural characterisation of drug-related compo nents. This work further serves to demonstrate the potential of coupling ta ndem mass spectrometry using an ion trap spectrometer with LC-NMR spectrosc opy, to provide an extremely powerful tool in structural elucidation. (C) 2 000 Elsevier Science B.V. All rights reserved.