Strong hydrophilic monolithic column functionalized with amphiphilic benzyl quinine for capillary electrochromatography and application in pharmaceutical analysis

An innovative strong hydrophilic organic polymer monolithic column of poly(N-benzylquininium chloride- co -1, 3, 5-triacryloylhexahydro-1, 3, 5-triazine) (poly(NBQ- co -TAT)) has been successfully synthesized through in situ copolymerization for capillary electrochromatography. The amphiphilic monomer NBQ and the strong polar cross-linker TAT are firstly used in hydrophilic electrochromatography by taking advantage of the exhibition of hydrophilicity at lower levels of organic solvent and ease formation of porous structure. The monolithic column poly(NBQ- co -TAT) shows powerful hydrophilic selectivity with mobile phase containing more than 60% organic solvent. The introduction of NBQ and TAT enlarges the sources of functional monomers and cross-linkers for HILIC. Due to the presence of the positively charged group in NBQ, an anodic electroosmotic flow is generated with the change of pH values from 2.0 to 12.0. The monolithic column was used for the separations of thioureas, phenols, xanthines, nucleobases, acidic substances and pharmaceuticals. The highest column efficiency for N, N′-dimethylthiourea is 1.15 × 10 5  N  m −1 . The application of the monolithic column for a real sample, cytochrome C digestion indicates its great potential in practical application.