Information about Fragmentations of Oligosaccharides Molecular Ions by Negative In-beam CI Method:

Using Microheater

Abstract

Negative in-beam CI mass spectra of several oligosaccharides were obtained by use of a heatable ceramic probe which was capable of heating rates up to 100°C/s and of temperatures up to 1000°C. In-beam ionization using this heating probe and a CI ion-source corresponds to “flash desorption CI” and made it possible to obtain not only the quasimolecular ion of stachyose but also cluster ions of glucose and sucrose. Accurate mass measurements of the molecular ion of maltotriose were successfully carried out. Linked scanning of the cluster ion, [2M-1]^- of glucose elucidated the fragmentation processes of the cluster ion involving successive losses of (CH₂O)_n and H₂O.