An improved method for galactosyl oligosaccharide characterization

•A significantly improved method for GOS characterization was developed.•The method uses a new small particle size column for HPAE.•Coupling HPAE with PAD and Orbitrap mass spectrometry yielded in depth information.•Resolution, especially in the disaccharide region, is significantly improved.•Effect of structure on elution behavior correlated using known oligosaccharides.