title: Controllable preparation of a hydrophilic/ion-exchange mixed-mode stationary phase by surface-initiated atom transfer radical polymerization using a mixture of two functional monomers.
abstract: Mixed-mode chromatographic stationary phases require functionalization with at least two functional groups to yield multiple interactions with analytes. Departing from reported methods, a mixture of two different monomers, glycidyl methacrylate and 2-dimethylaminoethylmethacrylate, was grafted onto the surface of silica by a one-step surface-initiated atom transfer radical polymerization to prepare a novel hydrophilic interaction/anion-exchange mixed-mode chromatographic stationary phase. The grafted amounts of functional groups were controlled via varying the ratio of monomers in the polymerization system. The influences of water content, salt concentration and pH in the mobile phase were investigated to illustrate the mixed interaction between the stationary phase and analytes. The retention of various solutes on three columns, especially acidic and basic solutes, showed an obvious dependence on the ratio of the two monomers in the polymerization system. The results indicated that the strategy proposed in this work was beneficial to develop various types of mixed-mode chromatographic stationary phases with adjustable selectivity to meet the needs of complex samples. Finally, the column was successfully employed in the isolation of melamine in liquid milk.
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry and Materials Science, Northwest University, Xi'an, P.R. China.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry and Materials Science, Northwest University, Xi'an, P.R. China.
authors.forename: Chunmiao
authors.initials: C
authors.lastname: Bo
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry and Materials Science, Northwest University, Xi'an, P.R. China.
authors.forename: Chaozhan
authors.initials: C
authors.lastname: Wang
authors.affiliation: Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Key Laboratory of Modern Separation Science in Shaanxi Province, College of Chemistry and Materials Science, Northwest University, Xi'an, P.R. China.
authors.forename: Yinmao
authors.initials: Y
authors.lastname: Wei
mesh_terms: D000818:Animals; D002852:Chromatography, Ion Exchange; D057927:Hydrophobic and Hydrophilic Interactions; D008892:Milk / Q000737:chemistry*; D058105:Polymerization; D012822:Silicon Dioxide; D014227:Triazines / Q000032:analysis*
chemical_list: D014227:Triazines; D012822:Silicon Dioxide; C011907:melamine
keywords: atom transfer radical polymerization; mixed-mode chromatography; stationary phases