title: Fragmentation of complex carbohydrates following ionization by matrix-assisted laser desorption with an instrument fitted with time-lag focusing.
abstract: Matrix-assisted laser desorption/ionization time-of-flight spectra of carbohydrates recorded with an instrument using time-lag focusing (delayed extraction) were found to exhibit fragment ions, whereas, in the non time-lag-focusing mode, fragment ions were not observed. Fragment ions consisted both of glycosidic and cross-ring cleavage products whose absolute, but not relative abundance increased with the delay time and indicated that they were formed within the ion source. Only the glycosidic cleavage ions were present in post-source decay spectra and their abundance was inversely correlated with the delay time. The results indicated that the cross-ring cleavages were predominately the products of fast reactions whereas the glycosidic cleavages occurred over a longer time frame.
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, UK.
authors.forename: T J
authors.initials: TJ
authors.lastname: Naven
authors.forename: D J
authors.initials: DJ
authors.lastname: Harvey
authors.forename: J
authors.initials: J
authors.lastname: Brown
authors.forename: G
authors.initials: G
authors.lastname: Critchley
mesh_terms: D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006027:Glycosides / Q000032:analysis; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002241:Carbohydrates; D006027:Glycosides; D009844:Oligosaccharides