title: Synthesis of surface Cr (VI)-imprinted magnetic nanoparticles for selective dispersive solid-phase extraction and determination of Cr (VI) in water samples.
abstract: A facile, rapid and selective magnetic dispersed solid-phase extraction (dSPE) method for the extraction and enrichment of Cr (VI) prior to flame atomic absorption spectrometry (AAS) was introduced. For highly selective and efficient extraction, magnetic Cr (VI)-imprinted nanoparticles (Fe3O4@ Cr (VI) IIPs) were prepared by hyphenating surface ion-imprinted with sol-gel techniques. In the preparation process, chromate (Cr(VI)) was used as the template ion; vinylimidazole and 3-aminopropyltriethoxysilane were selected as organic functional monomer and co-monomer respectively. Another reagent, methacryloxypropyltrimethoxysilane was adopted as coupling agent to form the stable covalent bonding between organic and inorganic phases. The effects of various parameters on the extraction efficiency, such as pH of sample solution, the amount of adsorbent, extraction time, the type and concentration of eluent were systematically investigated. Furthermore, the thermodynamic and kinetic properties of the adsorption process were studied to explore the internal adsorption mechanism. Under optimized conditions, the preconcentration factor, limit of detection and linear range of the established dSPE-AAS method for Cr (VI) were found to be 98, 0.29μgL-1and 4-140μgL-1, respectively. The developed method was also successfully applied to the analysis of Cr (VI) in different water samples with satisfactory results, proving its reliability and feasibility in real sample analysis.
authors.affiliation: Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, 94 Weijin Road, Tianjin 300071, PR China.
authors.forename: Xue
authors.initials: X
authors.lastname: Qi
authors.affiliation: Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, 94 Weijin Road, Tianjin 300071, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology (Nankai University), Tianjin, 300071, PR China. Electronic address: tanganna@nankai.edu.cn.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Ding
authors.affiliation: Research Center for Analytical Sciences, College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, 94 Weijin Road, Tianjin 300071, PR China.
authors.forename: An-Na
authors.initials: AN
authors.lastname: Tang
keywords: Cr (VI); Magnetic dispersed solid-phase extraction; Surface ion-imprinted