Preparation Of Magnetic Carbon Using Coated Polymer As Carbon Source And Its Adsorption Performance For Environmental Pollutants

The separation and enrichment of samples is a very important process in the analysis of complex samples.Compared with other pre-treatment methods,magnetic solid phase extraction(MSPE)can greatly simplify the phase separation procedure and increase the contact areas between analytes and adsorbents,which increase the mass transfer rate and extraction equilibrium.So,the exploration of new types of the MSPE adsorbents to improve the enrichment capability for different kinds of analytes has become an active field in analytical chemistry.With the properties of high surface area,high chemical and physical stability,carbon materials are currently finding its wide application in many fields including adsorbents,drug deliver,electrode materials,and catalyst supports.Recently,the magnetic carbon materials which combine the advantages of carbon materials and the feature of magnetic materials are widely used in adsorption trace organic compounds.Therefore,fabrication of magnetic carbon materials which have good adsorption performance is of particular interest in the field of synthesis the adsorbent.In this study,we fabricated magnetic carbon materials using two different methods.And,adsorbed different environmental pollutants using as-prepared adsorbent.The research includes:(1)Based on the mussel adhesive,the polydopamine-encapsulated magnetic nanoparticles(Fe3O4@PDA)were prepared.Then the carbon precursors were fabricated by using atom transfer radical polymerization to graft polystyrene and polyacrylonitrile from Fe3O4@PDA.After carbonization,the magnetic mesoporous carbon materials and N-doped magnetic carbon materials were obtained.The chemical composition,morphology and magnetism of the magnetic carbon materials were characterized.The as-prepared two magnetic carbon material were applied as adsorbent for the enrichment and analysis of chlorophenols.Compared the extraction efficiency of two adsorbents,the synthesis of magnetic carbon materials(MagC-PSt)by using of graft polystyrene as carbon sources was better than other adsorbent.So,we chose the MagC-PSt as adsorbents to enrichment the chlorophenols from environmental samples.Under the optimal experimental conditions,the recoveries of chlorophenols were in the range of 84.2%-120%with intra-and inter-relative standard deviations(RSD)lower than 10.0%.The results show that the proposed method is fast,convenient and have good recoveries.(2)We fabricated magnetic carbon materials by using metal-organic polymer(Fe3+-tannic)as carbon source.Compared with the methods by using polydopamine as carbon source to prepared magnetic carbon materials,this method was rapid,simple,low-cost and the surface areas of the as-prepared adsorbent was high.The as-prepared adsorbent was characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),Fourier-transform infrared spectrometer(FT-IR),X-ray photoelectron spectroscopy(XPS),powder X-ray diffraction(XRD)and N2 adsorption/desorption.In addition,we used the adsorbents for adsorption of phthalate acid esters(PAEs).Various parameters affecting the enrichment were investigated,such as,pH,extraction time and desorption time,type of elute solvents,amount of adsorbents.Compared with other methods for the determination of PAEs,the proposed method is fast,convenient and simple.