Characterization of Underivatized Pterins by Laser Desorption Fourier Transfonn Mass Spectrometry

Abstract

Laser desorption FfMS provides a powerful method for examining the structures of underivatized pteridines. (M + Na)+ and (M + K)+ ions are generated by laser desorption and can be used to determine molecular weights. The negative ion spectra provide more detailed structural information through an (M-H)- ion as well as a variety of fragment ions. The collisional dissociation spectra of these negative ions give detailed structural information which is determined by possible resonance structures for the specific ions. Deuterium exchange reactions were found to be quite useful to define fragmentation pathways.

Keywords

• underivatized pterins
• laser desorption
• . mass spectrometry