Sythesis Of Functionalized Magnetic Adsorbents Oriented By Applications In Separation And Analysis For Environmental And Biological Samples

The separation and analysis for trace analytes in complex samples(including environmental and biological samples) is a great challenge of modern analytical science, which attracts extensive attention in recent years. The complex samples are usually consisting of multi-components with big differences in physical and chemical properties, low concentrations, limited sample volumes in some fields(especially in biological area), and improper sample status. Therefore, analysis of trace analytes presented in such complex samples required appropriate sample pretreatments method before being injected into modern analytical instrumentations.At present, magnetic solid-phase extraction(MSPE) technique based on magnetic separation and functionalized magnetic nanoparticles(MNPs) sorbents, is one of the research hotspots for complex samples separation. Herein, in order to realize rapid and sensitive analysis for target analytes in complex samples, surface modifications of MNPs then developing functionalized magnetic sorbents which possess good selectivity, large adsorption capacity and high extraction efficiency are becoming key issues in the research on MSPE.Inspired by the points presented above, this paper proposed a facile and novel route to prepare two functionlized magnetic composites, and the resultant materials were applied for organic dyestuffs removal in environmental sewage and biomolecules enrichment in body fluid, repectiviely. The main contents of our work are as follows:1. The importance and necessity of sample pretreatment, the feature, classify, functionalization and application of magnetic composites and the principle, merits, operating procedures, operating patterns of(M)SPE were reviewed. The adsorbents for MSPE and the characteristics and application of graphene(oxide), Polyhedral Oligomeric Silsesquioxane(POSS), boronate affinity were also highlighted.2. Graphene oxide(GO) was prepared from graphite powder by modified Hummers’ method. Then the magnetic composites(Fe3O4-GO, M-GO) were fabricated via convenient and controllable self-assembly approach. The GO on the surface of Fe3O4 was then reduced by in-situ reduction and the magnetic functionalized reduced GO composite(M-RGO) was eventually obtained. The resultant materials were characterized by FT-IR, VSM and N2 adsorption/desorption. The adsorption performance and regeneration ability of various magnetic functionalized composites were evaluated and compared by taking organic dyestuffs(malachite green, rhodamine B, methylene blue) as probes.3. By utilizing of the rich chemistry of octavinyl-POSS, magnetic POSS(Fe3O4@POSS) composite was facilely prepared by free radical polymerization. A boronate functionalized magnetic hybrid adsorbent was constructed based on Fe3O4@POSS, herein the Fe3O4@POSS acted as a ―reaction platform‖. The resultant materials were characterized by SEM, FT-IR, N2 adsorption/desorption, ICP-AES and VSM. Using the materials as MSPE adsorbents, a boronate affinity magnetic solid-phase extraction method combined with high performance liquid chromatography(HPLC-UV) for the selective extraction of catecholamines(CAs) in human urine samples was established. Eventually, the proposed analytical method was successfully applied for enrichment and analysis of CAs in human urine.4. The research work in this article is summarized, and the prospects on the fabrication technology and application of novel functional hybrid derivatives based on magnetic materials are forecasted.