title: Preparation of silica-magnetite nanoparticle mixed hemimicelle sorbents for extraction of several typical phenolic compounds from environmental water samples.
abstract: A novel type of superparamagnetic silica-coated (Fe3O4/SiO2 core/shell) magnetite nanoparticle modified by surfactants has been successfully synthesized and was applied as an effective sorbent material for the pre-concentration of several typical phenolic compounds (bisphenol A (BPA), 4-tert-octylphenol (4-OP) and 4-n-nonylphenol (4-NP)) from environmental water samples. Compared with pure magnetic particles, a thin and dense silica layer would protect the iron oxide core from leaching out in acidic conditions. In order to enhance their adsorptive tendency towards organic compounds, cetylpyridinium chloride (CPC) or cetyltrimethylammonium bromide (CTAB) were added, which adsorbed on the surface of the Fe3O4/SiO2 nanoparticles (Fe3O4/SiO2 NPs) and formed mixed hemimicelles. Main factors affecting the adsolubilization of analytes were optimized and comparative study on the use of CPC and CTAB-coated Fe3O4/SiO2 NPs mixed hemimicelles-based SPE was also carried out. CPC-coated Fe3O4/SiO2 NPs system was selected due to lower elution volume required and more effective adsorption of the target compounds. Under selected conditions, concentration factor of 1600 was achieved by using this method to extract 800 mL of different environmental water samples. The detection limits obtained for BPA, 4-OP and 4-NP with HPLC-FLD were 7, 14, and 20 ng/L, respectively.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhao
authors.forename: Yali
authors.initials: Y
authors.lastname: Shi
authors.forename: Thanh
authors.initials: T
authors.lastname: Wang
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Cai
authors.forename: Guibin
authors.initials: G
authors.lastname: Jiang
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D002594:Cetylpyridinium / Q000737:chemistry; D052918:Environmental Restoration and Remediation / Q000379:methods*; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008280:Magnetics; D008823:Micelles; D053758:Nanoparticles / Q000737:chemistry*; D010636:Phenols / Q000302:isolation & purification*; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction; D012995:Solubility; D012996:Solutions; D013501:Surface-Active Agents / Q000737:chemistry; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D002593:Cetrimonium Compounds; D008823:Micelles; D010636:Phenols; D012996:Solutions; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D012822:Silicon Dioxide; D002594:Cetylpyridinium; D052203:Ferrosoferric Oxide; D000077286:Cetrimonium