One-step preparation of cyclen-containing hydrophilic polymeric monolithic materials via epoxy-amine ring-opening reaction and their application in enrichment of N-glycopeptides

Abstract Considering the special structure of 1,4,7,10-tetraazacyclododecane (cyclen) which is easy to form complexes with ions, it is beneficial to achieve particular selectivity. Cyclen was selected as a precursor to react with triglycidyl isocyanurate (TGIC), and a novel kind of hydrophilic polymeric monolithic material was facilely prepared via epoxy-amine ring-opening reaction in the presence of a binary porogenic system of acetonitrile (ACN) and polyethylene glycol. The resulting poly (TGIC-co-cyclen) monolithic column was used to separate both nonpolar alkylbenzenes using mobile phase of ACN/H2O (35/65, v/v) and polar phenolic compounds and anilines under the mobile phase of ACN/H2O (60/40, v/v) in reversed-phase capillary liquid chromatography (cLC). It should be pointed that the monolith was further used for separation of a mixture of toluene, DMF, acrylamide and thiourea under the mobile phase of ACN/H2O (95/5, v/v) by hydrophilic interaction chromatography (HILIC). These results indicated that the poly (TGIC-co-cyclen) column exhibited mixed-mode retention mechanism. As a result, the prepared monolithic material was employed for enrichment of glycosylated peptides from the tryptic digest of human immunoglobulin G (IgG) and serum protein tryptic digests. A total of 531 N-glycopeptides and 329 N-glycosylation sites, mapped to 166 glycoproteins, were identified from 2 μL human serum digest. The results indicated the prepared monolith had ability for enriching N-glycopeptides from complex biological samples.