title: Preparation of a nitro-substituted tris(indolyl)methane modified silica in deep eutectic solvents for solid-phase extraction of organic acids.
abstract: A new sorbent for solid-phase extraction was synthesized by chemical immobilization of nitro-substituted tris(indolyl)methane on silica in new and green deep eutectic solvents. Elemental analysis results indicated that deep eutectic solvents could be an alternative to the traditional solvents in preparing nitro-substituted tris(indolyl)methane modified silica. Coupled with high performance liquid chromatography, the extraction performance of the sorbent was evaluated by using four organic acids as model analytes. The rebinding experiments results showed that the nitro-substituted tris(indolyl)methane modified silica sorbent had a good adsorption capacity towards the selected organic acids. Under the appropriate experimental conditions, good precision and wide linear ranges with coefficient of determination (R(2)) of higher than 0.9957 were obtained, and the limits of detection were in the range of 0.50-2.0μgL(-1) for the organic acids tested. The developed solid-phase extraction-high performance liquid chromatography-diode array detection (SPE-HPLC-DAD) method was successfully applied for the determination of organic acids in two drinking samples with recoveries ranging from 76.7% to 110.0% and 67.7% to 104.0% for all the selected organic acids, respectively.
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Jiamin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liao
authors.affiliation: Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China. Electronic address: sjshao@licp.cas.cn.
authors.forename: Shijun
authors.initials: S
authors.lastname: Shao
keywords: Deep eutectic solvents; High performance liquid chromatography; Nitro-substituted tris(indolyl)methane; Organic acids; Solid-phase extraction