title: A magnetic sorbent for the efficient and rapid extraction of organic micropollutants from large-volume environmental water samples.
abstract: A magnetic solid-phase extraction (MSPE) method based on a novel magnetic sorbent was proposed for the extraction of target compounds from large-volume water samples. First, magnetic hypercrosslinked microspheres (NAND-1) were prepared via membrane emulsification-suspension polymerization and post crosslinking reaction. To ensure that the Fe3O4 nanoparticles could completely pass through the membrane without blocking the pores, oleic acid was used to modify the Fe3O4 nanoparticles, which enhanced lipophilicity and monodispersity of the magnetite nanoparticles. The obtained NAND-1 microspheres exhibited super paramagnetic characteristics and excellent magnetic responsiveness with a saturation magnetization of 2.53 emu/g. In addition, a uniform particle size (~8 μm) and a large average surface area (1303.59 m(2)/g) were also observed, which were both beneficial for the extraction of the target compounds. Thus, NAND-1 has the potential to simultaneously exhibit good extraction efficiencies toward different types of organic micropollutants (OMPs), including triazines, carbamazepine and diethyl phthalate. The conditions of the MSPE based on NAND-1 were optimized by single factor and orthogonal design experiments. This MSPE method needed only a small amount of sorbent (50mg/L) for the extraction of OMPs from a large-volume aquatic sample (5L) and reached equilibrium in a short amount of time (30 min). Moreover, the solution volume, the pH, and the salinity had insignificant influences on the extraction of the eight target OMPs. Under the optimum conditions, the recoveries of the eight OMPs calculated by analyzing the spiked samples were from 91.7% to 99.4%. The NAND-1 could be recycled ten times and still achieve recoveries of the eight OMPs higher than 86%. The limits of detection of the eight OMPs ranged from 1.76 to 27.56 ng/L, and the limits of quantification were from 5.71 to 92.05 ng/L. These results indicated that the proposed method, based on the use of NAND-1 as a magnetic sorbent, has the advantages of convenience and high efficiency and can be successfully applied to analyze the OMPs in real water samples.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Collaborative Innovation Center for Advanced Water Pollution Control Technology and Equipment, Nanjing 210023, China.
authors.forename: Mancheng
authors.initials: M
authors.lastname: Zhang
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
authors.forename: Chendong
authors.initials: C
authors.lastname: Shuang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Mengqiao
authors.initials: M
authors.lastname: Wang
mesh_terms: D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008863:Microspheres; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D015203:Reproducibility of Results; D045483:Rivers / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D006812:Humic Substances; D058185:Magnetite Nanoparticles; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical
keywords: Carbamazepine; Diethyl phthalate; High surface area; Magnetic solid-phase extraction; Membrane emulsification; Triazines