Photodissociation of peptide ions in a matrix-assisted laser desorption ionization reflectron time-of-flight mass spectrometer.

摘要

This study focuses on 193nm photodissociation of peptide ions with a delayed extraction matrix-assisted laser desorption ionization reflectron time-of-flight mass spectrometer. A mathematical model for simulating arrival time distributions of ions is presented and used for the design and development of the reflectron time-of-flight mass spectrometer used in the photodissociation studies of protonated peptide ions. The concepts of design and construction of a high performance tandem time-of-flight mass spectrometer are discussed. Results obtained with the new time-of-flight mass spectrometer are compared with a state of the art time-of-flight mass spectrometer to evaluate the performance. Photodissociation is applied to tandem mass spectrometry studies of protonated peptide ions. The photofragment ions observed are compared with unimolecular decay and CID fragmentation reactions and the utility of the photofragment ion spectrum for peptide sequencing is discussed.