两种磁性纳米复合材料的制备及其在环境医学中的应用研究

发布时间：2018-04-19 17:12

本文选题：界面共沉淀 + 溶胶-凝胶技术　；参考：《华中科技大学》2015年博士论文

【摘要】：二战以来,随着世界经济的飞速发展和人们生活水平的不断提高,工业、农业和居民生活排放使多种化学污染物进入环境水体,对水生生态系统造成严重破坏。特别是某些有机污染物,由于具有高毒性、生物蓄积性和环境持久性,通过饮水等多种途径进入人体,在机体组织器官中蓄积,并随血液循环和机体代谢引发多脏器功能紊乱,严重危害人体健康。农业产业化的发展使农产品的生产越来越依赖于农药、抗生素和激素等外源化学物质。这些化学物质的不合理使用将导致在农产品中的残留,人体摄食了残留超标的食品,将引发诸多不良反应,如急性毒性、过敏反应和内分泌紊乱,严重者导致器官病理性改变甚至癌变。因此,开展环境污染物和食品残留化学物监测,系统、客观地反映污染物动态变化和化学物存在水平,是评估人体暴露、评价人群健康危害、建立相关标准法规的前提条件,而有效的样品前处理技术是实现样品中痕量分析物准确定量的关键环节。本课题研究选择与人类生活密切相关的地表水中全氟化合物(Perfluorinated compounds. PFCs)和食品中大环内酯类抗生素(Macrlide antibiotics, MACs)为研究对象,逐步开展了两种具有选择性识别能力的磁性纳米复合材料的制备及在环境污染监测和食品安全领域的应用研究。本课题研究具体分为五个部分：第一章选择性识别全氟化合物的新型磁性纳米复合材料的制备及性能评价研究 F-F相互作用发生在分子的氟化段与高度氟化的流动相或固定相之间。近年来,这种作用已在物质的提纯和分离中有所应用。本研究首次将多氟单体和氨基单体结合,制备得到选择性识别PFCs的新型磁性纳米复合材料。首先采用改良的界面共沉淀法合成得到经-COOH修饰的Fe304纳米颗粒(Nanoparticles, NPs), Fe3O4-COOH NPs近似球形,尺寸分布较窄,平均粒径为10nm,能在水相介质中长期(2w)稳定分散。而后,以Fe3O4-COOH NPs为基底,利用溶胶-凝胶技术,“一步法”制备得到由-NH2和全氟辛基功能化的磁性纳米复合材料Fe3O4@SiO2-NH2F13。该磁性材料具有核壳结构,壳厚度在2nm左右。傅立叶变换红外光(Fourier transform-infrared, FT-IR)谱图中1560、1194和1145cm-1处的吸收峰证实了材料表面-NH2和C-F键的存在。Fe3O4@SiO2-NH2F13饱和磁化量(Saturated magnetization, Ms)为40.5emu g-1,能在外加磁场作用下快速分离。良好的亲水活性能有效抑制干扰化合物在磁性材料上的疏水性吸附。选择1H,1H,2H,2H-全氟-1-辛醇、正辛酸、邻氟苯乙酸、3,4-二羟基苯乙酸、氟苯尼考和红霉素作为参照化合物,评价了Fe3O4@SiO2-NH2F.3对PFCs的选择性识别能力,结果证实,该磁性材料基于静电作用、F-F相互作用以及尺寸排阻效应对PFCs表现出良好的选择性。分别选择乙醇和水作为吸附介质,得到Fe3O4@SiO2-NH2F13对PFCs的吸附等温线,并利用两种模型-Langmuir和Freundlich-进行拟合。结果表明,在乙醇中,该磁性材料对PFCs表现为单层吸附,吸附容量介于12.97-129.51mg g-1；在水中,除短链(C8)PFCs外,其余PFCs还可在磁性材料表面疏水聚集形成双层、半胶束和胶束结构,很大程度上提高了材料对PFCs的吸附容量,甚至对长链(C9)PFCs的吸附容量超过了1000mg g-1。因此,该磁性纳米复合材料将在PFCs痕量分析以及环境污染去除中表现出广阔的应用前景。第二章基于磁性固相萃取的快速检测技术用于东湖水体中全氟化合物的污染状况分析 PFCs在水相环境中广泛存在已成为一个不争的事实,大多数PFCs在水体多以ng L-1水平存在,建立快速、灵敏的检测技术是准确反映地表水体中PFCs污染状况的关键。本研究以第一章制备的Fe3O4@SiO2-NH2F13作为吸附剂,建立了一种简便、快速、高效的磁性固相萃取(Magnetic solid-phase extraction, MSPE)技术,并用于地表水体中9种PFCs的富集与净化,利用超高效液相色谱串联质谱检测对PFCs进行定量分析。在最优的MSPE条件下,500mL水样中的PFCs最终浓缩于0.5mL溶剂中,实现了对PFCs1000倍的富集效果。该方法的线性范围在0.097-100ng L-1之间,R20.9917,检测限介于0.029-0.099ng L-1。在0.5、5和50ng L-1的加标浓度下,PFCs加标回收率在90.05-106.67%之间,相对标准偏差介于3.11-12.62%。与利用Oasis-WAX (Mixed-mode weak anion exchanger)作为吸附剂的BS ISO25101:2009标准方法相比,水样经MSPE处理后,色谱基线更为平滑,基质干扰得到有效去除,PFCs的响应信号显著增强,实现了地表水体中PFCs的准确、灵敏性检测。环东湖郭郑、牛巢和汤菱三个湖区,分别沿湖岸选择8、6和3个有代表性的采样点,采用全球定位系统对采样点进行标记,利用上述建立的快速检测技术对水样中的PFCs进行检测,分析东湖水体中PFCs的污染状况。发现水体中PFCs的含量在30.12-125.35ng L-1之间,其中,全氟辛烷磺酸和全氟辛酸是主要的污染物,且PFCs污染以娱乐活动最多的牛巢区最为严重。尽管在大多数(70%)的受检水样中,全氟十一酸、全氟十二酸和全氟十四酸的含量低于方法定量限,但是由于湖体中沉积物和水生生物对长链(C8)PFCs的高浓度富集,提示在今后的研究中,有必要开展对东湖全方位、多角度、综合性的PFCs污染监测。第三章磁性纳米复合材料Fe3O4@SiO2-NH2F13选择性去除长江水体中全氟化合物的应用研究目前,在饮用水生产环节,对水源水传统的处理方式,如沙滤、臭氧化、氯化消毒、活性污泥净化,均不能去除水体中的PFCs。尽管一些先进的处理技术,如超声辐射、反相渗透,对PFCs表现出较好的去除效果,然而,从环保和经济层面考虑,功能材料吸附是去除水体中PFCs较为有效的技术。本研究进一步以第一章制备的Fe3O4@SiO2-NH2F,3作为选择性去除材料,系统研究了该磁性材料对长江水体中PFCs的去除效果。首先评价了时间、温度和酸碱度对该磁性材料吸附性能的影响。该磁性材料可在5min内达到对PFCs的平衡吸附,远小于阴离子交换树脂IRA67和粉末型活性碳(Powder acti vated carbon, PAC)对PFCs的吸附平衡时间；随着温度的升高,磁性材料对PFCs的吸附量有轻微降低,说明该材料对PFCs的吸附为放热过程；溶液pH对磁性材料的吸附性能有一定程度的影响,表现为随pH升高,材料对PFCs的吸附量逐渐降低,特别当pH10时,对短链(C10)PFCs吸附量急剧降低。将Fe3O4@SiO2-NH2F,3用于长江水体中PFCs的快速、选择性去除,同时与IRA67和PAC的去除效果进行比较。在1L加标浓度为0.5、5和50ng L-1的水样中,0.5h内,该磁性材料对水样中PFCs的去除率可达86.29%,远高于IRA67和PAC对PFCs的去除率,两者分别为12.86%和58.61%。而且,Fe3O4@SiO2-NH2F13对每种PFC均表现出良好的去除效果,除全氟辛烷磺酸(63.06-72.99%)和全氟庚酸(64.71-75.53%)外,其余PFCs的去除率均在80%以上。另外,与PAC相比,Fe3O4@SiO2-NH2F13能抵抗水体中高浓度腐植酸(Humicacid. HA)对去除效果的影响,当HA添加浓度为50mg L-1时,PFCs的去除率仅降低了9.81%,而PAC对PFCs的去除率却降低了41.48%。同时,Fe3O4@SiO2-NH2F13制备方法简便、便于磁性回收、可重复利用且对水体中PFCs的去除效果稳定。因而,该磁性材料在环境水体PFCs的污染去除中表现出了较强的实用价值。第四章选择性识别大环内酯类抗生素的磁性分子印迹复合材料的制备及性能评价研究分子印迹聚合物(Molecularly imprinted polymers, MIPs)基于其上印迹孔穴与目标分子间的形状匹配和官能团相互作用,能选择性识别模板分子及其结构类似物。而在Fe3O4NPs表面构建分子识别系统,将MIPs的选择性与Fe3O4NPs的优良特性相结合,提高了对目标分析物的吸附速率,同时吸附材料又可由外加磁场快速分离。本研究基于表面分子印迹技术,以Fe3O4NPs为基底,红霉素(Erythromycin, ERY)为模板分子,在Fe3O4NPs表面包被MTPs制备得到磁性分子印迹复合材料Fe3O4@SiO2@MIPsn该磁性材料具有核壳结构,FT-IR谱图中1734cm-1处明显的C=O伸缩振动峰表明MIPs在Fe3O4NPs表面的存在,同时,该磁性材料具有超顺磁性特征,Ms为3.2emu g-1。Scatchard分析Fe3O4@SiO2@MIPs对ERY的吸附特征,结果表明在磁性材料表面存在有异质性吸附位点,这些吸附位点对ERY具有不同的亲和力,同时,该磁性材料对ERY的吸附容量可达94.1mg g-1,印迹因子为11.9。选择食品中常见的氟喹诺酮类和酰胺醇类抗生素作为参照化合物,评价了Fe3O4@SiO2@MIPs对MACs的选择性,结果证实该磁性材料对多种MACs表现出良好的选择性,可作为MSPE吸附剂用于复杂样本的前处理。第五章磁性固相萃取-高效液相色谱-紫外检测法快速检测食品样本中大环内酯类抗生素的应用研究大多数MACs(如红霉素和阿奇霉素)缺少特异性的紫外生色基团,高效液相色谱紫外检测(High-performance liquid chromatography-ultraviolet detection)对MACs定量分析时常选择非特异性的低紫外吸收波长监测物质响应信号,为避免样品基质对紫外检测的干扰,实现MACs的选择性和灵敏性检测,有效的样品前处理至关重要。本研究将第四章制备的Fe3O4@SiO2@MIPs作为萃取吸附剂,建立了一种简便、快速的MSPE技术,用于选择性分离食品样本中6种MACSo100mg磁性材料加入到20mL样品提取液中,材料选择性萃取MACS;5min后,材料经磁性分离,由10mL乙腈：水(2：8,v/v)淋洗去除非选择性吸附的干扰化合物；10mL甲醇：50mMKH2PO4(pH8)(8:2, v/v)洗脱MACs,洗脱时间为2min,HPLC-UV对MACs定量分析。结果表明,在不同加标浓度下,MACs的萃取回收率可达89.1%,相对标准偏差低于12.4%;样品经MSPE处理后,色谱基线平滑,基质干扰得到有效去除,MACs响应信号显著增强。与其他将常规SPE技术与HPLC-UV联用检测食品样本中MACs的分析方法相比,本研究建立的MSPE-HPLC-UV方法有更低的检测限,避免了低紫外波长下样品基质对紫外检测的干扰,实现了猪肉、鱼肉和虾肉样本中多种MACs快速、准确、灵敏性检测。
[Abstract]:Since World War II, with the rapid development of world economy and the continuous improvement of people's living standards, industrial, agricultural and residential emissions have made a variety of chemical pollutants entering the environmental water body, causing serious damage to the aquatic ecosystem. In particular, some organic pollutants have high toxicity, bioaccumulation and environmental durability, through drinking water. And many other ways to enter the body, accumulate in the body tissues and organs, and lead to multiple organ dysfunction with blood circulation and body metabolism, which seriously endanger human health.
The development of agricultural industrialization makes the production of agricultural products more and more dependent on the foreign chemicals such as pesticides, antibiotics and hormones. The irrational use of these chemicals will lead to the residue in the agricultural products. The human body can feed the food with excess residue, which will lead to many adverse reactions, such as acute toxicity, allergic reaction and endocrine disorder. The organ causes pathological changes and even canceration of the organs.
Therefore, it is a prerequisite for evaluating the dynamic changes of pollutants and the existence level of chemicals, which is the prerequisite for evaluating the exposure of the human body, evaluating the health hazards of the population, and establishing the relevant standards and regulations, and the effective sample pretreatment technology is the key to the realization of the accurate quantitative analysis of the trace analyte in the sample. Key links. This subject studies the selection of Perfluorocompounds (Perfluorinated compounds. PFCs) and macrolide antibiotics (Macrlide antibiotics, MACs) in surface water, which is closely related to human life. The preparation and environmental pollution of two kinds of Magnetic Nanocomposites with selective recognition ability are gradually developed. Application research in the field of dyeing monitoring and food safety.
This research is divided into five parts:
Chapter 1 Preparation and performance evaluation of Novel Magnetic Nanocomposites with selective recognition of perfluorinated compounds
The interaction of F-F occurs between the fluorinated segments of the molecules and the highly fluorinated mobile phase or stationary phase. In recent years, this effect has been used in the purification and separation of materials. In this study, a new magnetic nano composite for selective identification of PFCs was prepared by combining the multi fluorine monomers with the amino monomers. -COOH modified Fe304 nanoparticles (Nanoparticles, NPs) were synthesized by surface co precipitation, and Fe3O4-COOH NPs was approximately spherical, with a narrow size distribution and an average particle size of 10nm, which could be stable and dispersed in the medium of water phase (2W). Then, Fe3O4-COOH NPs was based on the sol-gel technique, and the "one step method" was used to prepare from -NH2 and perfluorooxine. Based on the functionalized magnetic nanocomposite Fe3O4@SiO2-NH2F13., the magnetic material has a core shell structure with a shell thickness of about 2nm. The absorption peaks at 15601194 and 1145cm-1 in the Fu Liye transform infrared (Fourier transform-infrared, FT-IR) spectra confirm the.Fe3O4@SiO2-NH2F13 saturation magnetization of the -NH2 and C-F bonds on the surface of the material (Satura). Ted magnetization, Ms) is 40.5emu g-1, which can be separated rapidly under the effect of magnetic field. Good hydrophilic activity can effectively inhibit the hydrophobic adsorption of interfered compounds on magnetic materials. Select 1H, 1H, 2H, 2H- perfluoro -1- octanol, ortho octanoic acid, phthalic acid, 3,4- dihydroxy phenylacetic acid, florfenicol and erythromycin as reference compounds. The selective recognition ability of Fe3O4@SiO2-NH2F.3 to PFCs has been obtained. The results show that the magnetic material is based on electrostatic action, F-F interaction and size exclusion effect have good selectivity to PFCs. The adsorption isotherms of Fe3O4@SiO2-NH2F13 to PFCs are obtained by choosing ethanol and water as adsorbents, and two models of -Langmuir are used. The results show that the magnetic material is monolayer with the adsorption capacity of PFCs in ethanol, and the adsorption capacity is between 12.97-129.51mg g-1, and in water, in addition to the short chain (C8) PFCs, the remaining PFCs can also form a double layer, a semi micelle and a micelle structure on the surface of the magnetic material, which greatly improves the absorption of the material to the PFCs. The adsorption capacity of the long chain (C9) PFCs is more than 1000mg g-1., so the Magnetic Nanocomposites will have a broad application prospect in the trace analysis of PFCs and the removal of environmental pollution.
The second chapter analyzes the pollution of perfluorinated compounds in East Lake waters based on the rapid detection technology of magnetic solid phase extraction.
The widespread existence of PFCs in the water environment has become an indisputable fact. Most of the PFCs exists at the level of ng L-1 in the water body. Rapid and sensitive detection technology is the key to accurately reflect the status of PFCs pollution in the surface water body. In this study, the first chapter of the preparation of Fe3O4@SiO2-NH2F13 as an adsorbent, a simple, rapid and high level is established. The effective magnetic solid phase extraction (Magnetic solid-phase extraction, MSPE) technology was used for the enrichment and purification of 9 kinds of PFCs in the surface water. The quantitative analysis of PFCs was carried out by super high performance liquid chromatography tandem mass spectrometry. In the optimal MSPE condition, PFCs in 500mL water was concentrated in 0.5mL solvent and realized the rich of PFCs1000 times. The linear range of this method is between 0.097-100ng L-1, R20.9917, and the detection limit is between 0.029-0.099ng L-1. and 0.5,5 and 50NG L-1, and the recovery rate of PFCs plus standard is between 90.05-106.67%, and the relative standard deviation is between 3.11-12.62%. and using Oasis-WAX as adsorbent. Compared with the 2009 standard method, after the water sample was treated with MSPE, the baseline of the chromatography was more smooth, the matrix interference was effectively removed, the response signal of the PFCs was significantly enhanced, and the accuracy and sensitivity of PFCs in the surface water body were detected. The Three Lakes region of East Lake, ring East Lake, cattle nest and Tang Ling, selected 8,6 and 3 representative sampling points along the lake bank, and adopted the whole The ball positioning system marks the sampling point, and uses the rapid detection technology established above to detect the PFCs in water samples and analyze the pollution status of PFCs in East Lake water body. It is found that the content of PFCs in the water body is between 30.12-125.35ng L-1, among which perfluorooctane sulfonic acid and perfluorooctyl acid are the main pollutants, and PFCs pollution is entertaining. Most of the cattle nest areas are the most serious. Although the content of perfluoroacid eleven acid, perfluoro twelve acid and perfluoroacid fourteen acid is lower than the method quantitative limit in most of the (70%) samples, it is necessary to carry out all directions to East Lake because of the high concentration of sediments and aquatic organisms in the lake and aquatic organisms for the high concentration of long chain (C8) PFCs. Angle, comprehensive PFCs pollution monitoring.
The third chapter is about the selective removal of perfluorinated compounds in the Yangtze River water by magnetic nanocomposite Fe3O4@SiO2-NH2F13.
At present, in the drinking water production link, the traditional treatment of water source water, such as sand filtration, ozonation, chlorination disinfection and activated sludge purification, can not remove the PFCs. in water body, although some advanced treatment techniques, such as ultrasonic radiation, reverse phase infiltration and better removal effect on PFCs, are shown, however, from the environmental and economic level, the functional material is considered. Material adsorption is a more effective technique for removing PFCs in water. This study has further studied the removal effect of the magnetic material for the removal of PFCs in the Yangtze River with Fe3O4@SiO2-NH2F and 3 as a selective removal material. First, the effects of time, temperature and pH on the adsorption properties of the magnetic material were evaluated. The material can reach the equilibrium adsorption of PFCs in 5min, which is much less than the adsorption equilibrium time of the anion exchange resin IRA67 and the powder type active carbon (Powder acti vated carbon, PAC) on PFCs. As the temperature increases, the adsorption of magnetic materials to PFCs decreases slightly, indicating that the adsorption of the material to PFCs is the exothermic process, and the solution pH is magnetic. The adsorption property of the material has a certain influence. The adsorption capacity of the material to PFCs gradually decreases with the increase of pH. Especially when pH10, the adsorption capacity of the short chain (C10) PFCs is sharply reduced. Fe3O4@SiO2-NH2F, 3 is used for the rapid and selective removal of PFCs in the Yangtze River water, and compared with the removal efficiency of IRA67 and PAC at the same time. The concentration of the standard concentration in 1L is in the 1L. In the water samples of 0.5,5 and 50NG L-1, the removal rate of PFCs in water samples can reach 86.29% in 0.5h, which is far higher than IRA67 and PAC for PFCs removal, both are 12.86% and 58.61%., respectively. Fe3O4@SiO2-NH2F13 shows good removal efficiency for each PFC, except PFOS (63.06-72.99%) and perfluorohepic acid. In addition, the removal rate of the remaining PFCs is above 80%. In addition, compared with PAC, Fe3O4@SiO2-NH2F13 can resist the effect of high concentration humic acid (Humicacid. HA) on the removal efficiency. When HA adding concentration is 50mg L-1, the removal rate of PFCs is only 9.81%, while PAC to PFCs reduces the 41.48%.. The method is simple and convenient for magnetic recovery. It can be reused and has a stable removal effect of PFCs in water body. Therefore, the magnetic material has shown strong practical value in the pollution removal of PFCs in environmental water body.
The fourth chapter is the preparation and evaluation of magnetic molecularly imprinted composites for selective identification of macrolides antibiotics.
Molecular imprinted polymer (Molecularly imprinted polymers, MIPs) can selectively identify template molecules and their structural analogues based on the shape matching and functional group interaction between the upper imprinted holes and the target molecules. The molecular recognition system is constructed on the Fe3O4NPs surface, and the selectivity of MIPs and the excellent properties of Fe3O4NPs are combined and improved. The adsorption rate of the target analyte and the adsorption material can be separated rapidly by the external magnetic field. Based on the surface molecularly imprinted technique, Fe3O4NPs is used as the substrate and erythromycin (Erythromycin, ERY) is the template molecule, and the magnetic molecularly imprinted composite Fe3O4@SiO2@MIPsn, the magnetic material, is prepared on the Fe3O4NPs surface by MTPs. With nuclear shell structure, the obvious C=O stretching vibration peak at 1734cm-1 in the FT-IR spectrum indicates the existence of MIPs on the Fe3O4NPs surface. At the same time, the magnetic material has superparamagnetic characteristics. Ms is a 3.2emu g-1.Scatchard to analyze the adsorption characteristics of Fe3O4@SiO2@MIPs to ERY. The results show that there is a heterogeneous adsorption site on the surface of the magnetic material and these adsorption sites are found on the surface of the magnetic material. It has different affinity to ERY, and the adsorption capacity of the magnetic material to ERY can reach 94.1mg g-1, and the imprinting factor is 11.9. selected as the common fluoroquinolone and amidoalcohol antibiotics as reference compounds, and the selectivity of Fe3O4@SiO2@MIPs to MACs is evaluated. The results show that the magnetic material is good for a variety of MACs. The selectivity can be used as a MSPE adsorbent for pretreatment of complex samples.
The fifth chapter is the application of magnetic solid phase extraction high performance liquid chromatography Ultraviolet Detection for rapid detection of macrolide antibiotics in food samples.
Most MACs (such as erythromycin and azithromycin) lack specific ultraviolet chromogenic groups, and high performance liquid chromatography (High-performance liquid chromatography-ultraviolet detection) often selects non specific low ultraviolet absorption wavelength monitoring material response signal to MACs quantitative analysis, in order to avoid the sample matrix to UV detection. It is very important to detect the selectivity and sensitivity of MACs. Effective sample preprocessing is very important. In this study, the Fe3O4@SiO2@MIPs as an extractant in fourth chapters was used as an extractant, and a simple and rapid MSPE technology was established for the application of 6 MACSo100mg magnetic materials in selective separation food samples to 20mL sample extract. After selective extraction of MACS, after 5min, the material was separated by magnetic separation, and the non selective adsorptive compounds were removed by 10mL acetonitrile: water (2:8, v/v) leaching; 10mL methanol: 50mMKH2PO4 (pH8) (8:2, v/v) elution MACs, and the elution time was 2min. The relative standard deviation was less than 12.4%; after MSPE treatment, the baseline was smooth, the matrix interference was effectively removed, and the MACs response signal was significantly enhanced. Compared with the other MACs analysis methods that used conventional SPE technology and HPLC-UV combined with the detection of food samples, the MSPE-HPLC-U was established in this study.

【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1;R12

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