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Separation of basic and acidic compounds by capillary electrochromatography using monolithic silica capillary columns with zwitterionic stationary phase
Author(s) -
Hu Jiwei,
Xie Chuanhui,
Tian Ruijun,
He Zhike,
Zou Hanfa
Publication year - 2007
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200600173
Subject(s) - capillary electrochromatography , monolith , chemistry , monolithic hplc column , electrochromatography , chromatography , phase (matter) , capillary electrophoresis , electrophoresis , capillary action , electro osmosis , analytical chemistry (journal) , stationary phase , materials science , organic chemistry , catalysis , composite material
A novel monolithic silica column with zwitterionic stationary phase was prepared by in‐situ covalent attachment of phenylalanine to a 3‐glycidoxypropyltriethoxysilane‐modified silica monolith. Due to the zwitterionic nature of the resulting stationary phase, the density and sign of the net surface charge, and accordingly the direction and magnitude of electroosmotic flow in this column during capillary electrochromatography could be manipulated by adjusting the pH values of the mobile phase. CEC separations of various acidic and basic compounds were performed on the prepared column in anodic and weakly cathodic EOF modes, respectively. The peak tailing of basic compounds in CEC on a silica column could be alleviated at optimized buffer compositions. Besides the electrophoretic mechanism and weak hydrophobic interaction, weak cation‐ and anion‐exchange interactions are also involved in the separations of acids and bases, respectively, on the zwitterionic column.