Glycosylation primarily refers to the enzymatic process of linking polysaccharides to proteins, lipids, or other organic molecules, and is the most common type of post-translational modification (PTM). Due to the complexity and isoform nature of the linked polysaccharides, glycan analysis presents significant challenges. As protein therapeutics such as monoclonal antibodies, glycoproteins, hormones, cytokines, and coagulation factors are increasingly used in clinical practice, the detection of protein N-gly