The Preparation Of Nano Fe₃O₄ Magnetic Polymer Microspheres And Their Application In Magnetic Solid Phase Extraction

Magnetic polymer microspheres have both the properties of polymers and magnetic materials.The copolymerization and surface modification can introduce the surface functional groups in the surface of magnetic materials,such as-OH,-COOH,-CHO,-NH2,-SH,etc.,moreover it is rapidly and easily isolated by the external magnetic field.Because the modified magnetic materials have the advantages of adsorption properties and good separation,it has been increasingly used for the sample pretreatment in analytical chemistry.In this paper,magnetic polymer microspheres were prepared by dispersive polymerization and they were used as magnetic solid phase extraction materials in the pretreatment process of complex samples.Selective,sensitive and rapid analytical methods for the determination of some trace compounds in urine,orange juice,cosmetics samples were established.The main content of this paper is as follows:(1)Fe3O4 nanoparticles were synthesized by chemical co-precipitation of Fe3+ ang Fe2+under basic condition,and then were coated by SiO2 by a modified Stober method.The composite was synthesized by dispersion polymerization.The structure and extraction performance of the magnetic polymer microspheres were evaluated by infrared spectrum and HPLC.Then this material was applied to separation and concentration of BPs in urine samples.By optimizing the extraction conditions,high selectivity analytical method for separation of benzophenones in urine had been developed.The experimental results showed that the linear ranges were 0.05-300 ng/mL for benzophenones in urine with the correlation coefficient of above 0.9966.The detection limits(s/n=3)was 0.05 ng/mL.(2)Fe3O4@SiO2 microspheres were prepared by sol-gel method and then magnetic silica colloids with surface modification by y-Methacryloxypropyl trimethoxy silane were synthesized.This composite material was prepared by dispersion polymerization of MAA and EGDMA in the presence of Fe3O4@SiO2@MPS microspheres with the surface containing abundant reactive double bonds.The resultant sorbent material was characterized by infrared spectrum and was applied to separation and concentration of carbaryl,isoprocarb and carbofuran in orange juice samples.By optimizing the extraction conditions,high selectivity analytical method for the determination of carbaryl,isoprocarb and carbofuran in orange juice had been developed.(3)The superficial modified materials were prepared by dispersion polymerization of methacrylic acid and EGDMA in the presence of Fe3O4@SiO2@MPS microspheres containing abundant reactive double bonds in its surface.The resultant sorbent materials were characterized by infrared spectrum and were applied to separation and concentration of benzophenone,2-hydroxyl-4-methoxybenzophenone,and 2,4-dihydroxybenzophenone in cosmetics samples.By optimizing the extraction conditions such as the volume of sample,the type of extraction solvent,the extraction time and so on.High selectivity analytical method for separation of BPs in cosmetics samples had been developed.