title: A rapid and simple pretreatment method for benzoylurea insecticides in honey samples using in-syringe dispersive liquid-liquid microextraction based on the direct solidification of ionic liquids.
abstract: A pretreatment method using in-syringe dispersive liquid-liquid microextraction based on the direct solidification of ionic liquids before high performance liquid chromatography analysis was developed for the determination of benzoylurea insecticides (BUs) in honey samples. The hydrophobic ionic liquid [N4444][PF6], formed in situ by the hydrophilic ionic liquid [N4444]Cl and the ion exchange reagent KPF6, was used to extract the target analytes. The entire extraction procedure was performed in a syringe. The extractant was solidified at room temperature and collected using a nylon membrane filter. This technique did not require a dispersive solvent, vortex mixer, ultrasound bath, or centrifugation. The parameters affecting the extraction efficiency were investigated through an experimental design. Under the optimal conditions, the limits of detection for the four BUs varied from 0.21 to 0.42μgL-1in solution (2.1-4.2μgkg-1in honey). Good linearities were obtained in the range of 2-300μgL-1, with coefficients of determination greater than 0.999. The recoveries of the four BUs ranged from 80.94% to 84.59%. The intra-day (n=3) and inter-day (n=3) relative standard deviations were less than 5.08%. Finally, the proposed method was applied to the determination of BUs in commercial honey samples with satisfactory results.
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing, 100193, China.
authors.forename: Huazi
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing, 100193, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing, 100193, China.
authors.forename: Wanzhen
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing, 100193, China.
authors.forename: Runhua
authors.initials: R
authors.lastname: Lu
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing, 100193, China.
authors.forename: Sanbing
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing, 100193, China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Applied Chemistry, College of Science, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing, 100193, China. Electronic address: hxgao@cau.edu.cn.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Gao
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005504:Food Analysis / Q000295:instrumentation* / Q000379:methods*; D006722:Honey / Q000032:analysis*; D007306:Insecticides / Q000032:analysis*; D052578:Ionic Liquids / Q000737:chemistry*; D057230:Limit of Detection; D059627:Liquid Phase Microextraction / Q000295:instrumentation; D012997:Solvents / Q000737:chemistry; D013594:Syringes
chemical_list: D007306:Insecticides; D052578:Ionic Liquids; D012997:Solvents
keywords: Benzoylurea insecticides; Direct solidification; Dispersive liquid–liquid microextraction; Honey; Ionic liquids