title: In situ metathesis reaction combined with liquid-phase microextraction based on the solidification of sedimentary ionic liquids for the determination of pyrethroid insecticides in water samples.
abstract: A novel dispersion liquid-liquid microextraction method based on the solidification of sedimentary ionic liquids (SSIL-DLLME), in which an in situ metathesis reaction forms an ionic liquid (IL) extraction phase, was developed to determine four pyrethroid insecticides (i.e., permethrin, cyhalothrin, fenpropathrin, and transfluthrin) in water followed by separation using high-performance liquid chromatography. In the developed method, in situ DLLME was used to enhance the extraction efficiency and yield. After centrifugation, the extraction solvent, tributyldodecylphosphonium hexafluorophosphate ([P44412][PF6]), was easily collected by solidification in the bottom of the tube. The effects of various experimental parameters, the quantity of tributyldodecylphosphonium bromide ([P44412]Br), the molar ratio of [P44412]Br to potassium hexafluorophosphate (KPF6), the ionic strength, the temperature of the sample solution, and the centrifugation time, were optimized using a Plackett-Burman design to identify the significant factors that affected the extraction efficiency. These significant factors were then optimized using a central composite design. Under the optimized conditions, the recoveries of the four pyrethroid insecticides at four spiked levels ranged from 87.1% to 101.7%, with relative standard deviations (RSDs) ranging from 0.1% to 5.5%. At concentration levels between 1 and 500 µg/L, good linearity was obtained, with coefficients of determination greater than 0.9995. The limits of detection (LODs) for the four pyrethroid insecticides were in the range of 0.71-1.54 µg/L. The developed method was then successfully used for the determination of pyrethroid insecticides in environmental samples.
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China.
authors.forename: Panjie
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China.
authors.forename: Wanyu
authors.initials: W
authors.lastname: Shan
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China.
authors.forename: Songqing
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Yuanmingyuan West Road 2#, Haidian District, Beijing 100194, China. Electronic address: hxgao@cau.edu.cn.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Gao
mesh_terms: D007306:Insecticides / Q000032:analysis / Q000302:isolation & purification; D052578:Ionic Liquids / Q000737:chemistry*; D059627:Liquid Phase Microextraction / Q000379:methods*; D011722:Pyrethrins / Q000032:analysis* / Q000302:isolation & purification*; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification
chemical_list: D007306:Insecticides; D052578:Ionic Liquids; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Central composite design; Dispersion liquid–liquid microextraction; High performance liquid chromatography; In situ metathesis; Pyrethroid insecticides; Solidification of sedimentary ionic liquids