title: Ultrasound-assisted magnetic solid-phase extraction based ionic liquid-coated Fe3O4@graphene for the determination of nitrobenzene compounds in environmental water samples.
abstract: An ultrasound-assisted magnetic solid-phase extraction procedure with the [C7MIM][PF6] ionic liquid-coated Fe3O4-grafted graphene nanocomposite as the magnetic adsorbent has been developed for the determination of five nitrobenzene compounds (NBs) in environmental water samples, in combination with high performance liquid chromatography-photodiode array detector (HPLC-PDA). Several significant factors that affect the extraction efficiency, such as the types of magnetic nanoparticle and ionic liquid, the volume of ionic liquid and the amount of magnetic nanoparticles, extraction time, ionic strength, and solution pH, were investigated. With the assistance of ultrasound, adsorbing nitrobenzene compounds by ionic liquid and self-aggregating ionic liquid onto the surface of the Fe3O4-grafted graphene proceeded synchronously, which made the extraction achieved the maximum within 20 min using only 144 μL [C7MIM][PF6] and 3 mg Fe3O4-grafted graphene. Under the optimized conditions, satisfactory linearities were obtained for all NBs with correlation coefficients larger than 0.9990. The mean recoveries at two spiked levels ranged from 80.35 to 102.77%. Attributed to the convenient magnetic separation, the Fe3O4-grafted graphene could be recycled many times. The proposed method was demonstrated to be feasible, simple, solvent-saving and easy to operate for the trace analysis of NBs in environmental water samples.
authors.affiliation: Research Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou, 310014, China. xiaojicao@zjut.edu.cn mowm@zjut.edu.cn.
authors.forename: Xiaoji
authors.initials: X
authors.lastname: Cao
authors.forename: Lingxiao
authors.initials: L
authors.lastname: Shen
authors.forename: Xuemin
authors.initials: X
authors.lastname: Ye
authors.forename: Feifei
authors.initials: F
authors.lastname: Zhang
authors.forename: Jiaoyu
authors.initials: J
authors.lastname: Chen
authors.forename: Weimin
authors.initials: W
authors.lastname: Mo
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D009578:Nitrobenzenes / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods*; D014465:Ultrasonics; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005290:Ferric Compounds; D052578:Ionic Liquids; D009578:Nitrobenzenes; D014874:Water Pollutants, Chemical; C000499:ferric oxide; D006108:Graphite