Ion-Mobility Mass Spectrometry of Glycans and Glycopeptides Using Both Intact and Glycan Sequencing Approaches In Positive Ion Mode Facilitates Glycan Isomer and Glycan Motif Identification

High resolution glycan analysis has become an important part of biopharmaceutical API production and quality control. Liquid chromatography (LC) is now a well-established technique in this field but the resolution of similar isomeric glycan structures is still a challenge. Here we show that the addition of ion mobility spectroscopy (IMS) in a hyphenated LC-IMS-MS setting allows for the high resolution of N-glycan isomers during positive ion analysis. We have identified unique features in the IM chromatograms to help differentiate a range of isomeric N-glycans for both RFMS labelled glycans and glycopeptides.