ANALYSIS OF PERMETHYLATED GLUCOSAMINYL-GLUCOSAMINITOL DISACCHARIDES BY COMBINED GAS-LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY

The α‐and β‐forms of permethylated 1,3‐, 1,4‐ and 1,6‐linked N‐acetylglucosaminyl‐N‐acetylglucosaminitol disaccharides have been analysed directly (without hydrolysis or further modifications) by combined gas‐liquid chromatography mass spectrometry. Gas‐liquid chromatography facilitated the separation of the α‐ and β‐isomers of each disaccharide pair. In every case, the respective α‐form was slower than the β‐form. While, additionally, the α‐ and β‐forms of the 1,6‐linked glucosamine disaccharide could be separated from those of the 1,3‐ and 1,4‐linked disaccharides, the α‐ and β‐forms of the latter two could not be resolved from each other with the liquid phases used. All three disaccharides could be readily differentiated and characterized by mass spectrometry, however. Specific fragments for each glucosamine disaccharide could be defined. Therefore, combined gas‐liquid chromatography mass spectrometry allowed an unequivocal determination of the anomeric configuration and the position of the glycosidic linkage in the glucosamine disaccharides. Copyright © 1979 Heyden & Son Ltd