Abstract

Milk oligosaccharides derivatized by reductive amination with benzylamine followed by N,N-dimethylation (DMBA-oligosaccharides), were analyzed by high-performance liquid chromatography/electro spray ionization ion-trap mass spectrometry (HPLC/ESI-ITMS). Separation of DMBA-oligosaccharides was achieved on a graphitized carbon column eluted with aqueous acetonitrile and the DMBA-oligosaccharides were detected by positive-ion mode ESI-ITMS allowing sample amounts down to similar to 30 fmol of single DMBA-oligosaccharides injected on the HPLC column. MS/MS operation of the mass spectrometer resulted in the detection of diagnostic fragments, mainly belonging to the Y-series, allowing differentiation between isomeric milk oligosaccharides. HPLC/ESI-ITMS/MS/MS experiments indicated the migration of fucose residues of the DMBA milk oligosaccharides to the modified reducing end glucose residue during analysis, a migration previously only observed for proton adduct ions. (c) 2007 Published by Elsevier Ltd

Keywords

Graphitized carbon column; Oligosaccharides; Reductive amination; Electrospray ionization; Ion-trap mass spectrometry; Fucose migration; Milk oligosaccharides

Published in

Carbohydrate Research
2007, volume: 342, number: 11, pages: 1462-1469
Publisher: ELSEVIER SCI LTD

Authors' information