Preparation Of Imidazolium Bromide Modified MNPs And Its Adsorption For PAHs

Ionic liquids as a new "green solvent" have fabricability and researchers can obtain some special functional ionic liquids by changing their physical and chemical properties to meet the needs of specific applications.The development of ionic liquids limits their development because of their poor separation,purification and high viscosity.To solve these problems,people usually load them on the surface of solid material.Due to the unique magnetic properties and excellent physicochemical properties of magnetic nanoparticles,the synthesis of magnetic solid phase extraction materials with novel functionalized ionic liquids has become a hot topic.Magnetic solid phase extraction materials can rapidly and accurately enrich and separate the pollutants in the sample,and can be reused after cleaning.The ionic liquids with different carbon chain length were synthesized by one-step synthesis method,and modified to the surface of magnetic nanoparticles prepared by functional magnetic nano materials,will eventually be applied to the extraction of PAHs in water samples.The main content of the paper is briefly as follows:(1)The ionic liquid as the characteristics of "green solvents",summarizes the problems of environmental organic pollutants pretreatment method and the existence,especially the functional magnetic solid phase extraction material application in sample pretreatment;according to the environmental priority pollutant polycyclic aromatic hydrocarbons(PAHs)analysis is discussed.(2)By "one-step synthesis method" anhydrous prepared two novel imidazolium ionic liquids,namely1-hexadecyl-3-alkyl triethoxy silane propyl imidazolium bromide ionic liquid([HDTIm]Br)and 1-octadecyl-3-alkyl triethoxy silane propyl imidazolium bromide ionic liquid([ODTIm] Br).Their structures were characterized by nuclear magnetic resonance(NMR),Fu Liye transform infrared spectroscopy(FTIR)and elemental analysis.(3)Under the protection of nitrogen,alkaline environment were prepared by ionic liquids [HDTIm]Br and [ODTIm]Br modified magnetic nanoparticles(MNPs)surface preparation of magnetic solid phase extraction material [HDTIm]Br-MNPs and [ODTIm]Br-MNPs.The preparation materials were characterized by Fourier transform infrared spectroscopy(FTIR),thermal gravimetric analysis(TG),X ray diffraction(XRD),transmission electron microscopy(TEM)and magnetic properties analysis(VSM).(4)15 kinds of polycyclic aromatic hydrocarbons(PAHs)were taken as the research object,and the magnetic solid phase extraction material [HDTIm]Br-MNPs method was established.The linear range was0.02~100.0 ng/mL,and the detection limit(LOD)was 0.901~129ng/L.Under the optimum conditions,effects of extraction of Xinxiang Lake Makino and West Lake Institute of science and technology in PAHs in [HDTIm]Br-MNPs,the recovery rate of 8.51~105.39%,the relative standard deviation(Relation standard deviation,1.70~10.10%,RSD)with satisfactory results.(5)15 kinds of polycyclic aromatic hydrocarbons(PAHs)were used as the object of study,and a MSPE-HPLC-FLD analysis method for [ODTIm]Br-MNPs was established.The linear range was0.02~100.0 ng/mL,and the detection limit(LOD)was 0.342~336 ng/L.Under the optimum conditions,the extraction of PAHs in Xinxiang city in Makino Lake [ODTIm]Br-MNPs,the recovery rate of4.21~109.90%,RSD 0.91~10.58%;materials to study science and Technology Institute in West Lake water PAHs extraction,the recovery rate of 5.37~109.55%,RSD 0.13%~12.79%,with satisfactory results.(6)The differences in the characterization of two kinds of magnetic solid materials[TDTIm]Br-MNPs,[ODTIm]Br-and MNPs were investigated.In addition,two kinds of magnetic solid phase extraction materials [TDTIm]Br-MNPs and [ODTIm]Br-MNPs with different lengths of carbon chains were compared.The extraction and extraction properties of PAHs in water under the same extraction conditions were compared.