Application Of Three Kinds Of Magnetic Nanoparticles Modified With Imidazole Ionic Liquids In Enviromental Water Samples Analysis

Magnetic solid-pahse extraction?MSPE?has been widely used for preconcentration of trace pollutants from environmental waters attributed to the advantage of convenient operation,low solvent consumed and recyclable adsorbents.The vital part of MSPE is the magnetic adsorbent.Ionic liquids-modified magnetic nanoparticles,with structural designability and functionalization,have aroused great attention in sample pretreatment area.Firstly,methylimidazoleionicliquid-modified magneticnanoparticles?Fe₃O₄@SiO₂@[MIM]Cl?were synthesized by silanization method.And an ultrasound-assisted magnetic solid-phase extraction method based on this adsorbent was developed to determine eight pyrethroids in environmental water samples,coupled with gas chromatography-tandem mass spectrometry?GC-MS/MS?.Several factors related to the extraction efficiencies,such as the amount of magnetic adsorbent,extraction time,the concentration of salt,and pH were optimized.Under the optimum conditions,the LODs and LOQs for eight pyrethroids were 0.02-2.70?g/L and 0.07-9.10?g/L,respectively.The mean recoveries at three spiked levels were in the range of79.3%-108.6%.The proposed method was proved to be simple and efficient,and the Fe₃O₄@SiO₂@[MIM]Cl could be recycled more than 5 times under pH 5-9.However,the Fe₃O₄@SiO₂@[MIM]Cl nanoparticles were unstable under the strongly acidic or alkali condition.Secondly,the reticular imidazole polyionic liquid-modified magnetic nanoparticles?Fe₃O₄@SiO₂@PIL-B?was designed and used as the magnetic adsorbent.An ultrasound-assisted magnetic solid-phase extraction method based on this adsorbent was developed for the determination of seven phenols in environmental water samples,in combination with GC-MS/MS.Six factors related to extraction efficiencies such as amount of adsorbent and extraction time etc.were optimized by response surface methodology?RSM?.Under the optimum conditions,the LODs and LOQs for the seven phenols were 0.07-2.63?g/L and 0.23-8.77?g/L,respectively.The mean recoveries at three spiked levels were in the range of 69.3%-108.9%.Moreover,the Fe₃O₄@SiO₂@PIL-B was could be recycled under the strongly acidic or alkali condition.Finally,the phenyl group contained-reticular imidazole polyionic liquid-modified magnetic nanoparticles?Fe₃O₄@SiO₂@PIL-C?was designed and used as the magnetic adsorbent.An ultrasound-assisted magnetic solid-phase extraction method based on this adsorbent was developed to determine nine polycyclic aromatic hydrocarbons?PAHs?in environmental water samples,in combination with GC-MS/MS.Six factors related to extraction efficiencies,such as amount of adsorbent,and extraction time etc.were investigated by RSM.Under the optimum conditions,the LODs and LOQs for the nine PAHs were 0.17-2.44 ng/L and 0.57-8.14 ng/L,respectively.Except for naphthalene and acenaphthylene,the mean recoveries for the other PAHs were in the range of71.46%-105.91%.The results demonstrated that Fe₃O₄@SiO₂@PIL-C is usable under the strongly acidic or alkali environment,and can effectively adsorb PAHs through?-?interactions.