title: An immobilized carboxyl containing metal-organic framework-5 stationary phase for open-tubular capillary electrochromatography.
abstract: A novel capillary column with metal-organic framework-5 (MOF-5) as the stationary phase was prepared for open-tubular capillary electrochromatography (OT-CEC). To grow MOF-5, the fused-silica capillary was functionalized firstly using 3-aminopropyltriethoxysilane and glutaraldehyde as covalent linkers; and then MOF-5 would be immobilized on the inner wall of COOH-terminated capillary by epitaxial growth, to produce a MOF-5-modified capillary. The successful growth of MOF-5 has been characterized and confirmed by scanning electron microscopy, X-Ray diffraction and Fourier transform infrared spectra. The influence of pH value and methanol on electroosmotic flow (EOF) of the MOF-5-modified capillary column was investigated. The EOF showed a pH-dependent from anode to cathode. The immobilization of MOF-5 improved the interactions between analytes and layer on inner wall of the capillary. Excellent separations of substituted benzenes and acidic and basic analytes were obtained on the fabricated capillary columns. The MOF-5-modified capillary columns exhibited good repeatability, with relative standard deviations for intra-day, inter-day runs and column-to-column less than 1.87%, 3.53%, and 8.49%, respectively. Our successful application of MOF-5 paved the way for introducing series of dicarboxylate-based isoreticular MOFs to OT-CEC as novel stationary phase.
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China; State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Beijing 10080, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Bao
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China.
authors.forename: Pingxiu
authors.initials: P
authors.lastname: Tang
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China.
authors.forename: Zhenkun
authors.initials: Z
authors.lastname: Mao
authors.affiliation: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China; State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Beijing 10080, China. Electronic address: chenzl@whu.edu.cn.
authors.forename: Zilin
authors.initials: Z
authors.lastname: Chen
keywords: Electrochromatographic column; MOF-5; Open-tubular capillary electrochromatography; Stationary phase