Determination of Linkage Position and Anomeric Configuration in Glucose-Containing Disaccharide Alditols by Multivariate Analysis of Data from Mass Spectrometry

Eight reducing glucose-containing disaccharides were analyzed by gas chromatography and electron ionization mass spectrometry as peracetylated and permethylated alditols. Data obtained, i.e., mass numbers and their relative intensities together with the retention times, were subjected to pattern recognition using multivariate data analysis. The data analysis revealed that linkage position between residues could be obtained. After the linkage position had been established the anomeric configuration was determined. The entire mass spectra were used for the calculations, but only five or less fragment ions had a major influence on the determination of the linkage position and anomeric configuration. All relevant fragments had relative abundance above 2%. The results also imply that, in the disaccharides investigated, an axial glycosidic bond is more easily cleaved in the ionization process than a corresponding equatorial.