title: In situ solvent formation microextraction combined with magnetic dispersive micro-solid-phase extraction for the determination of benzoylurea insecticides in water samples.
abstract: A simple, fast, effective, and environmentally friendly method, in situ solvent formation microextraction combined with magnetic dispersive micro-solid-phase extraction for the determination of four benzoylurea insecticides is presented herein for the first time. In the proposed method, 1-hexyl-3-methylimidazolium bis[(trifluoromethane)sulfonyl]imide was formed by the reaction between 1-hexyl-3-methylimidazolium chloride and lithium bis[(trifluoromethane)sulfonyl]imide and was used to extract benzoylurea insecticides. Then magnetic nanoparticles were added as carrier to retrieve and separate the ionic liquid from the sample solution. After the supernatant was removed, the ionic liquid was desorbed using acetonitrile and subsequently injected directly into a high-performance liquid chromatograph equipped with a variable wavelength detector for analysis. The main factors affecting the extraction efficiency were investigated by a one factor at a time approach. Under optimized conditions, the proposed method showed good repeatability (RSD = 2.2-4.5%) and linearity (2-300 μg/L), with correlation coefficients greater than 0.9994 and low limits of detection (0.67-1.46 μg/L). Finally, the method was successfully applied to the analysis of four benzoylurea insecticides in environmental water samples with good recoveries (73.2-85.8%).
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing, P.R. China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Yang
authors.affiliation: National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, P.R. China.
authors.forename: Jiankang
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing, P.R. China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing, P.R. China.
authors.forename: Runhua
authors.initials: R
authors.lastname: Lu
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing, P.R. China.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Gao
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing, P.R. China.
authors.forename: Sanbing
authors.initials: S
authors.lastname: Zhang
keywords: benzoylurea insecticides; ionic liquids; magnetic nanoparticles; microextraction