磁性氧化石墨烯的制备及其对环境水样中酚类物质的残留分析和吸附性能研究

发布时间：2018-02-27 05:10

本文关键词： 磁性纳米复合物磁性固相萃取酚类污染物吸附高效液相色谱　出处：《华中师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：环境中污染物往往以痕量水平存在其中,且样品基质复杂,因此需要采取萃取分离、净化、富集等前处理手段去除基质干扰,提高目标分析物的检测灵敏度。液液萃取(LLE)和固相萃取(SPE)是人们常用的样品前处理技术。然而,液液萃取耗时,需要大量的有毒有机溶剂。固相萃取通常比液液萃取消耗的有机溶剂少,但耗时、价格相对昂贵。近年来兴起了一种基于固相萃取的磁性固相萃取技术(Magnetic solid-phase extraction,MSPE)。此技术克服了传统固相萃取装柱和样品上样的繁琐和耗时、吸附剂用量大等缺点。磁性纳米材料具有良好的磁响应性、粒径小和比表面积大等优点,使其可以用于分离富集环境中的酚类污染物。本论文旨在制备新型的磁性纳米材料和发展磁性固相萃取(MSPE)技术。通过核壳结构的磁性铁纳米线(Fe@Fe_2O_3)与氧化石墨烯(GO)之间的静电相互作用,成功制备了磁性Fe@Fe_2O_3/G复合纳米粒子,并将其用于环境水样中酚类物质的残留分析和吸附性能研究。内容如下:1.采用改进的Hummer方法制备了 GO,采用文献的方法制备了 Fe@Fe203铁纳米线,通过GO与Fe@Fe_2O_3之间静电相互作用,成功地制备了磁性Fe@Fe203/GO复合纳米粒子。Fe@Fe_2O_3,GO和磁性Fe@Fe_2O_3/GO复合纳米粒子的结构、磁性和微孔结构采用扫描电镜(SEM)、傅里叶红外光谱(FTIR)、透射电镜(TEM)、磁化强度(VSM)、X射线粉末衍射(XRD)、Zeta电位、氮气吸附脱附曲线(BET)表征。2.以Fe@Fe_2O_3/GO作为磁性固相萃取的吸附剂,磁性固相萃取结合高效液相色谱法检测环境水样中的三种内分泌干扰素酚类物质。对吸附剂的类型和用量,样品溶液pH,萃取时间、解吸液种类及体积、材料的稳定性等作了深入研究。结果表明:三种酚类分析物在0.5-100 ng/mL时具有较好的线性关系,检出限(LODs)(S/N = 3)为0.08-0.10 ng/mL。日内和日间相对标准偏差(RSDs)小于7.5%。南湖水和垃圾水中未检测出三种酚类,在工厂水中检测到了双酚A和2,4-二氯酚,浓度分别为1.32,0.64 ng/mL。南湖水,垃圾水,工厂水加标浓度为5,10,50 ng/mL时,回收率在82%-94.8%之间。该方法成功应用于环境水样中三种酚类残留的分析检测。3.以BPA,DCP作为酚类的代表,研究Fe@Fe_2O_3/GO的吸附性能。通过对吸附时间,温度,pH和离子强度等影响吸附效率的因素进行考察。结果表明:在1h时,吸附达到平衡,动力学数据符合拟二级吸附动力模型;在研究范围内,碱性,加盐条件下均不利于吸附;Fe@Fe203/GO对BPA,DCP的吸附是个自发的放热过程,吸附量随着温度的增加而减小,吸附热力学数据符合Langmuir吸附模型,是均匀的单分子层吸附;在298.15K条件下,Langmuir吸附模型计算的Fe@Fe203/GO对BPA,DCP的最大吸附容量分别为88.5mg/g,125mg/g,高于文献中其它的碳质材料对BPA,DCP的吸附容量。
[Abstract]:The pollutants in the environment often exist at trace levels and the sample matrix is complex. Therefore, it is necessary to remove matrix interference by pre-treatment, such as extraction, separation, purification, enrichment and so on. Improving the detection sensitivity of target analytes. Liquid-liquid extraction (Lle) and solid phase extraction (SPE) are commonly used sample pretreatment techniques. However, liquid-liquid extraction is time consuming. A large number of toxic organic solvents are required. Solid-phase extraction usually consumes less organic solvents than liquid-liquid extraction, but takes less time than liquid-liquid extraction. In recent years, a magnetic solid-phase extraction technique based on solid phase extraction (SPE) has been developed. The magnetic nanomaterials have the advantages of good magnetic response, small particle size and large specific surface area. The aim of this thesis is to prepare new magnetic nanomaterials and develop magnetic solid phase extraction (MSPE) technology. FeFeFe2O3 and graphene oxide (GFAC) were prepared by core-shell structure magnetic iron nanowires (FeFe2O3) and graphene oxide (GOO). The electrostatic interaction between them, The magnetic Fe@Fe_2O_3/G composite nanoparticles were successfully prepared and used for the residue analysis and adsorption study of phenols in environmental water samples. The contents are as follows: 1. GOO was prepared by improved Hummer method, and Fe@Fe203 iron nanowires were prepared by the method of literature. By electrostatic interaction between go and Fe@Fe_2O_3, the structures of magnetic Fe@Fe203/GO composite nanoparticles, FeFeR\ + +\ +\ {2} O\ +\ {3} O\ + 3Go\ +\ +\ {{$}}\ $_ 2\ ^ 2\ +\%\ +\ {. The magnetic and micropore structures were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray powder diffraction (XRD), and nitrogen adsorption and desorption curve (BET). Fe@Fe_2O_3/GO was used as adsorbent for magnetic solid phase extraction (SPE). Magnetic solid phase extraction (SPE) combined with high performance liquid chromatography (HPLC) was used to determine three kinds of endocrine interferon phenols in environmental water samples. The results show that the three phenolic analytes have a good linear relationship at 0.5-100 ng/mL. The detection limit was 0.08-0.10 ng / mL 路day and day relative standard deviation (RSDs) < 7.5. No three phenols were detected in South Lake water and garbage water. Bisphenol A and 2o 4-dichlorophenol were detected in factory water with concentrations of 1.32 卤0.64 ng / mL 路south lake water, solid waste water, and waste water, respectively. The recovery rate was between 82% and 94.8% when the standard concentration of factory water was 5 ~ 10 ~ 10 ~ 50 ng/mL. The method was successfully applied to the determination of three phenols residues in environmental water samples. The adsorption performance of Fe@Fe_2O_3/GO was studied by using BPADCP as the representative of phenols. The temperature, pH and ionic strength were investigated. The results showed that the adsorption reached equilibrium at 1 h, and the kinetic data were in accordance with the pseudo-second-order adsorption kinetic model. The adsorption of BPADCP by Febo Fe203 / go is a spontaneous exothermic process, and the adsorption amount decreases with the increase of temperature. The adsorption thermodynamic data accord with the Langmuir adsorption model and are homogeneous monolayer adsorption. At 298.15K, the maximum adsorption capacity of Fe@Fe203/GO for BPA-DCP is 88.5 mg / g / g, which is higher than that of other carbon materials in the literature.
【学位授予单位】：华中师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X832;O658.2;TB383.1

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