Structural analysis of chromophore-labeled disaccharides by capillary electrophoresis tandem mass spectrometry using ion trap mass spectrometry

Disaccharides tagged with p-aminobenzoic acid (ABA) were separated by capil lary electrophoresis (CE) and analyzed on-line with negative ion electrospr ay ionization tandem mass spectrometry (ESI/MS/MS). The formation of glycos ylamine instead of reductive amination was selected as the derivatization r eaction. In negative ion ESI, the glycosylamine approach provides more info rmation on linkage and anomeric configuration than reductive amination. In CE analysis of ABA-labeled disaccharides, alpha-cyclodextrin (CD) was found to play a crucial role in the separation of linkage isomers. Although ammo nium acetate/alpha-CD provided the best resolution of linkage isomers, the berate buffer was superior to alpha-CD in the separation of disaccharides w ith the same linkage but different anomeric configuration and/or monosaccha ride composition. Both alpha-CD and berate suppressed the ion signal in ESI , and operational conditions were successfully obtained using 10 mM (alpha- CD or 10 mM berate. CT Am Soc Mass Spectrom 2000, 11, 292-300) (C) 2000 Ame rican Society for Mass Spectrometry.