title: Novel imidazolium-embedded and imidazolium-spaced octadecyl stationary phases for reversed phase liquid chromatography.
abstract: Two new stationary phases modified by alkylimidazoliums were prepared for the first time and characterized. One of the new phases was obtained via monomeric immobilization of octadecylimidazole to γ-chloropropyltrimethoxysilane modified silica to form polar-embedded phase; the other one was prepared by co-immobilization of two silane coupling agents (γ-chloropropyltrichlorosilane and octadecyltrichlorosilane) to silica, followed by quaternization of methylimidazole to form polar-spaced phase. This study was intended to compare the retention characteristics of these two stationary phases using linear solvation energy relationships model, as well as to examine the difference in selectivity by eluting alkylbenzenes, alkylnaphthalenes, condensed-ring and phenylene polynuclear aromatic hydrocarbons on both phases. Different effects of distributions of polar functional group and octadecyl chain were found to impact the chromatographic properties.
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Mingliang
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Tongnian
authors.initials: T
authors.lastname: Gu
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: hdqiu@licp.cas.cn.
authors.forename: Hongdeng
authors.initials: H
authors.lastname: Qiu
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: sxjiang@lzb.ac.cn.
authors.forename: Shengxiang
authors.initials: S
authors.lastname: Jiang
keywords: Linear solvation energy relationships; Polar-embedded; Polar-spaced; Reversed-phase liquid chromatography; Surface-confined ionic liquid