title: Magnetic retrieval of ionic liquids: fast dispersive liquid-liquid microextraction for the determination of benzoylurea insecticides in environmental water samples.
abstract: A novel, rapid ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) technique combined with magnetic retrieval (MR-IL-DLLME) has been developed and used to analyze five benzoylurea insecticides (BUs) in environmental water samples. This procedure was based on the magnetic retrieval of the ionic liquid using unmodified magnetic nanoparticles (MNPs). In this experiment, the fine ionic liquid droplets formed in aqueous samples functioned as an extractant for the extraction of BUs; after the extraction process was completed, Fe₃O₄ MNPs were added as a 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 an HPLC system for analysis. The optimum experimental parameters are as follows: 20 mg of Fe₃O₄ (20 nm) as magnetic sorbents; 70 μL of [C₆MIM][PF₆] as the extraction solvent; 300 μL of acetonitrile as the disperser solvent; a vortex extraction time of 90 s with the vortex agitator set at 2800 rpm and no ionic strength. Under the optimized conditions, good linearity was obtained with correlation coefficients (r) greater than 0.9981. The repeatability and reproducibility of the proposed method were found to be good, and the limits of detection ranged from 0.05 μg L⁻¹ to 0.15 μg L⁻¹. The proposed method was then successfully used for the rapid determination of BUs in real water samples. The recoveries of five BUs at two spiked levels ranged from 79.8 to 91.7% with RSDs less than 6.0%.
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China.
authors.forename: Jiaheng
authors.initials: J
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Miyi
authors.initials: M
authors.lastname: Yang
authors.forename: Bing
authors.initials: B
authors.lastname: Peng
authors.forename: Yubo
authors.initials: Y
authors.lastname: Li
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhou
authors.forename: Haixiang
authors.initials: H
authors.lastname: Gao
authors.forename: Runhua
authors.initials: R
authors.lastname: Lu
mesh_terms: D001549:Benzamides / Q000032:analysis* / Q000302:isolation & purification; D007093:Imidazoles / Q000737:chemistry; D007306:Insecticides / Q000032:analysis* / Q000302:isolation & purification; D052578:Ionic Liquids / Q000737:chemistry*; D060106:Lakes / Q000737:chemistry; D059627:Liquid Phase Microextraction / Q000379:methods*; D008280:Magnetics / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D009994:Osmolar Concentration; D015203:Reproducibility of Results; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D001549:Benzamides; D007093:Imidazoles; D007306:Insecticides; D052578:Ionic Liquids; D058185:Magnetite Nanoparticles; D014874:Water Pollutants, Chemical