Fragmentation of neutral oligosaccharides in negative-ion MALDI mass spectrometry

Abstract

Neutral oligosaccharides were analyzed by negative-ion matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). The characteristics of fragmentation in the mass spectrometer were studied, and a new structural analysis method was established. In negative-ion MALDI-MS, the fragmentation mechanism normally includes high-energy processes. By controlling the internal energy of the precursor ion in the ion trap, these characteristics of fragmentation were changed. Fragmentation from negatively charged oligosaccharides showed identical fragment patterns, depending on linkage type and branching pattern. This analysis method offered structural information which was fundamentally unobtainable using positive ion MALDI-MS. Negative-ion MALDI-MS analyses of neutral oligosaccharides are expected to be widely used in the structural analysis of oligosaccharides. ©2006 FCCA (Forum: Carbohydrates Coming of Age).