Methods of Ultraviolet Photodissociation for Mass Spectrometry

摘要

A method is described that involves simplification of UVPD mass spectra and comprises selecting precursor ions for UVPD fragmentation, performing UVPD fragmentation on selected precursor ions to give UVPD fragment ions. PTR may then be performed on the UVPD fragment ions with optional ion parking to yield charge-state reduced UVPD fragment ions. The UVPD-PTR steps may be repeated above n times where n=1 to 50. Ion parking may enhance the intensity of selected lower fragment ion charge states or to increase the intensity of peaks in selected m/z ranges. After a number of PTR-UVPD iterations, fragment ions are mass analyzed. The method provides a way of simplifying UVPD mass spectral product ions by lowering fragment ion charge states and spreading out resulting product ions in m/z mass spectral space when compared to using UVPD fragmentation alone.