Enrichment And Determination Of Typical Environmental Pollutants With Core-shell Nanomaterials Based On Nanoscale Zero-valent Iron

With the development of industry,more and more pollutants are discharged into the environment.But people's environmental awareness is growing and more attention is paid to potential health hazards of environmental pollutants.Many environmental pollutants are relatively stable and can be accumulated in human body for a long time through food chain.So they can cause harm to human body even at trace level.Therefore,the determination of environmental pollutants is a hot topic in recent years.Because of the complexity of environmental medium,low concentration present in environment,the determination of environmental pollutants always need both advanced detection technology and sample pretreatment technology.Magnetic sold phase extraction?MSPE?is a new preparation technology with many characteristics such as easy operation,high enrichment factor,reusable,environmentally friendly,and so on.Therefore it has great application prospect in the environmental field.Nanoscale zero-valent iron?NZVI?is a kind of attractive materials due to its high reactive activity and big specific surface area,and it has been widely used in the field of environmental engineering.NZVI has superparamagnetism and a lot of active sites,which can be easily to carry out surface functionalization.Hence it will have wide application in magnetic sold phase extraction.However,there were few reports about it.In this thesis,two kinds of novel magnetic materials were synthesized through surface modification and functionalization of NZVI,and which were used as adsorbents to develop new magnetic solid phase extraction methods in combination with high performance liquid chromatography?MSPE-HPLC?for the determination of typical environmental pollutants.The thesis can be divided into three parts:In the first part,Fe@SiO₂@PDA magnetic nanoparticles were prepared and characterized,and which was used to develop a novel MSPE-HPLC method for enrichment and determination of Sudan I-IV from environmental water samples.Under the optimal conditions,linear responses were obtained in the range of 0.01-50?g·L^-1,and the detection limits were in the range of 2.0-5.2 ng·L^-1.The proposed method was validated with real water samples,and the spiked recoveries in the range of 78.3-116.8%were achieved.In the second part,Fe@rGO magnetic nanoparticles were prepared and investigated to be used as the adsorbent of MSPE to establish a new MSPE-HPLC method for enrichment and determination of 4-phenylazophenol,p-aminoazobenzene and o-aminoazotoluene from environmental water samples.Under the optimal conditions,linear responses were obtained in the range of 0.0005-50?g·L^-1,0.001-50?g·L^-1,and 0.01-50?g·L^-1,respectively.The detection limits were in the range of2.0-5.2 ng·L^-1,and satisfied spiked recoveries in the range of 71.8-106.3%were achieved.In the third part,a novel MSPE-HPLC method for enrichment and determination of deltamethrin,fenvalerate and permethrin from environmental water samples with Fe@rGO magnetic nanoparticles.Under the optimal conditions,linear responses were obtained in the range of 1-50?g·L^-1,and the detection limits were in the range of0.15-0.28?g·L^-1.The proposed method was evaluated with real water samples and the spiked recoveries in the range of 76.8-106.7%were achieved.