Title

Improved Capillary Electrophoresis Separation and MS Detection of Oligosaccharides

Document Type

Article

Publication Title

Journal of Chromatography, A

Department

Chemistry

ISSN

0021-9673

Volume

1004

Issue

1--2

DOI

10.1016/S0021-9673(03)00718-0

First Page

121

Last Page

129

Publication Date

7-1-2003

Abstract

We have developed a CE method for the separation of structural isomers of oligosaccharides labeled with N-quaternized benzylamine. Oligosaccharides with reducing ends were derivatized with benzylamine by reductive amination followed by quaternization to yield a fixed cation label. The benzylamine-derivatized oligosaccharides were analyzed by CE–UV in ammonium acetate buffer and off-line matrix-assisted laser desorption ionization (MALDI) MS. The method was applied to a 1 nmol sample of a model oligosaccharide (LNDFH 1). From this sample a 38 fmol diluted standard was detected. The quaternization of benzylamine-labeled products significantly improved CE separation of neutral oligosaccharides along with several structural isomers. Two hexasaccharide isomers (LNDFH I and LNDFH II) were baseline resolved using an ammonium acetate buffer. This method was also applied successfully to the profiling of oligosaccharides released from the glycoprotein RNase B. The release of 6 pmol of glycans followed by workup showed the detection of all components, with one component corresponding to 100 fmol. Micropreparative collection of CE enabled successful off-line CE–MALDI-MS without additional sample clean up. This report provides a simple and rapid method to separate and analyze oligosaccharides.