title: Magnetic solid phase extraction based on magnetite/reduced graphene oxide nanoparticles for determination of trace isocarbophos residues in different matrices.
abstract: A simple one-step solvothermal method was applied for the preparation of magnetite/reduced graphene oxide (MRGO), and the synthetic nanocomposites with a magnetic particle size of ∼8nm were used as an adsorbent for magnetic solid phase extraction of isocarbophos (ICP) in different sample matrices prior to gas chromatography (GC) detection. The identity of the nanomaterial was confirmed using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It was shown that Fe3O4 nanoparticles with a uniform size were homogeneously anchored on RGO nanosheets. Increased oxidation degrees of graphite oxide, big particle sizes and large loading amounts of Fe3O4 on the surface of RGO led to a decrease of adsorption capacity of MRGO to ICP. The adsorption behavior of this adsorbent was better fitted by the pseudo-second-order kinetic model. Several parameters affecting the extraction efficiency were investigated and optimized, including adsorbent dosage, extraction time, ionic strength and desorption conditions. And then, a rapid and effective method based on MRGO combined with GC was developed for the determination of ICP in aqueous samples. A linear range from 0.05 to 50ngmL(-1) was obtained with a high correlation coefficient (R(2)) of 0.9995, and the limit of detection was found to be 0.0044ngmL(-1). This method was successfully applied to the analysis of ICP in five kinds of samples, including apple, rice, lake water, cowpea and cabbage. The recoveries in different sample matrices were in the range from 81.00% to 108.51% with relative standard deviations less than 9.72%. It can be concluded that the proposed analytical method is highly-efficient, sensitive, precise, accurate and practicable.
authors.affiliation: Key Laboratory of Environment Correlative Dietology (Ministry of Education), College of Food Science & Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Yan
authors.affiliation: Key Laboratory of Environment Correlative Dietology (Ministry of Education), College of Food Science & Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Qi
authors.affiliation: National Center of Quality Supervision and Inspection for Commodity, Yiwu, Zhejiang 322000, China.
authors.forename: De-Wen
authors.initials: DW
authors.lastname: Chen
authors.affiliation: Key Laboratory of Environment Correlative Dietology (Ministry of Education), College of Food Science & Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Environment Correlative Dietology (Ministry of Education), College of Food Science & Technology, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: lixj78@126.com.
authors.forename: Xiu-Juan
authors.initials: XJ
authors.lastname: Li
authors.affiliation: Key Laboratory of Environment Correlative Dietology (Ministry of Education), College of Food Science & Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Si-Yi
authors.initials: SY
authors.lastname: Pan
mesh_terms: D000327:Adsorption; D004785:Environmental Pollutants / Q000032:analysis*; D006108:Graphite / Q000737:chemistry*; D007306:Insecticides / Q000032:analysis*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D008294:Malathion / Q000031:analogs & derivatives* / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010573:Pesticide Residues / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D004785:Environmental Pollutants; D007306:Insecticides; D058185:Magnetite Nanoparticles; D010573:Pesticide Residues; C549713:isocarbophos; D006108:Graphite; D008294:Malathion
keywords: Gas chromatography; Graphene; Isocarbophos; Magnetic solid phase extraction; Magnetite; Nanoparticles