I'm not sure if I understand your question, but I think it will be difficult to identify a glycoprotein using HPAEC-PAD. That technique is better suited to analyze glycans, for example those released from a glycoprotein by a glycosidase. The resulting protein can then be identified using mass spectrometry, for example.
It can only be used for the purpose of glycan profiling as indicated...Also, the analysis platform may be a good option for monosaccharide analysis...Intact mode glycoprotein analysis would not be ok...High sensitivity is a significant advantage and without fluorophore agents as derivatizing molecules, glycans which are released from glycoprotein by endo-glycosidases (also O-glycans can be monitored if the chemical approach has been used) can be analyzed at low levels...deprotonated glycans are separated by anion exchange and detected by amperometric responses...different RTs and responses other than HILIC-HPLC-FLD platform are obtained, therefore a comprehensive standard mixture of glycans is needed to characterize the glycoprotein structure...