Chromatographic evaluation and application of silica based azide-modified stationary phase under hydrophilic interaction liquid Chromatography mode.

Hydrophilic interaction liquid chromatography (HILIC) has attracted more and more interests in recent years. However, the stationary phases for HILIC are still scarce. More stationary phases and separation methods should be developed. Silica based azide-modified stationary phase was synthesized and characterized by our group. The nucleosides were selected as the test samples. The retention property of nucleosides on the azide-modified stationary phase was shown with typical HILIC characterization. Moreover, the glycopeptide selectivities of azide-modified stationary phase under HILIC mode by adding two species of salts (ammonium bicarbonate and ammonium formate) and acid in mobile phase were compared. The results showed that better glycopeptide selectivity could be obtained under acid condition without adding salt in the mobile phase. With the optimized conditions, nine MS signals of glycopeptides were detected after enrichment from the tryptic digest of horseradish peroxidase (HRP). Silica based azide-modified stationary phase has the potential in further application in glycopeptide enrichment under HILIC mode.