Identification of N -glycan positional isomers by combining IMS and vibrational fingerprinting of structurally determinant CID fragments

-glycans with a terminal galactose attached to either the α-3 or α-6 branch, and in the case of G1F a fucose attached to the reducing-end GlcNAc. Starting with just a few analytical standards, this fragment-based spectroscopy method allows us to develop a database which we can use to identify positional isomers. The generalization of this approach would greatly facilitate glycan analysis.