DETERMINATION OF LINKAGE POSITION IN PER-O-METHYLATED XYLOOLIGOSACCHARIDES BY MIKE AND CID MASS-SPECTRA OF AMMONIA AND METHYLAMINE CLUSTER IONS

The linkage types 1-->2, 1-->3, and 1-->4 of D-xylobioses can be disti nguished based on the unimolecular decomposition spectra (MIKE) of the cluster [M + NH4](+) ions or by collision-induced dissociation (CID) mass spectra of [M + CH3NH3](+) ions of per-O-methylated compounds. Th e MIKE spectra of [M + NH4](+) and [M + CH3NH3](+) adducts allow the d etermination of linkage positions between the xylose residues in per-O -methylated o-xylotrioses. The branching point of the branched trisacc harides can be deduced from these mass spectra, too.