几种纳米材料在农药残留和有机污染物分析方面的应用

发布时间：2018-12-27 12:11

【摘要】：农药和有机污染物在样品中的含量比较低,但是对人体和其它生物存在着潜在的危害。环境样品基质复杂,一般需要通过样品处理过程,把目标分析物从复杂基质中分离并且富集后才能进行后续的定性定量分析。现有的样品前处理方法耗时、繁琐,常用的检测方法通常需要比较昂贵的仪器,分析成本较高且需要专业人员操作。因此,开发简单、快速、廉价的样品前处理方法和检测方法十分重要。纳米材料具有巨大的比表面积和独特的光学特性等,可以用于环境样品的前处理和检测。本论文主要分为三部分实验内容。第一部分:选取水果和蔬菜样品为基质,研究了石墨烯在农药多残留分析中的净化作用。首先,制备的石墨烯通过光电子能谱和拉曼光谱进行表征。然后,选取17种农药用GC-MS分析,研究了石墨烯作为QuEChERS方法的分散固相萃取吸附剂,对胡萝卜、葡萄、番茄、油菜四种基质的净化效果。实验结果表明:目标农药的回收率为92-120%,石墨烯对各种基质都有较好的净化作用,且其净化效果要优于石墨化炭黑。第二部分:选取15种邻苯二甲酸酯为目标分析物,研究了石墨烯对水体中环境污染物的提取作用。15种邻苯二甲酸酯用GC-MS检测,实验对石墨烯用量、解吸附溶剂、吸附时间、解吸附时间及pH进行了优化,并将该方法用于中国7个地方的河水和海水样本的分析。实验结果表明:在优化条件下,15种邻苯二甲酸酯在超纯水、河水、海水中的回收率为71-117%,方法的线性关系良好,且可以用于实际样本检测。第三部分:选取对氧磷为代表性的农药,研究了纳米材料在有机磷农药检测方面的应用。对制备的MnO2纳米片、碳量子点、金纳米颗粒进行了 TEM、UV-Vis光谱、荧光光谱、Zeta电位等表征。MnO2纳米片能够引起异硫氰酸荧光素(FITC)的荧光淬灭且该淬灭作用会随着H202的加入而得到恢复,H2O2可以通过乙酿胆碱酯酶和胆碱氧化酶的催化作用产生。基于有机磷农药抑制胆碱酯酶活性的性质,以对氧磷为例,建立了 FITC-MnO2纳米片荧光传感检测有机磷农药的方法。该方法的线性关系良好,LOD为1μg L-1,河水和自来水中的添加回收率为89-108%。相对于有机荧光染料,碳量子点低毒,生物相容性好。金纳米颗粒能够通过荧光共振能量转移作用(FRET)淬灭碳量子点荧光,丁酰胆碱酯酶水解硫代乙酰胆碱的产物能够引起金纳米颗粒聚沉,从而使碳量子点荧光恢复。基于有机磷农药抑制丁酰胆碱酯酶活性的性质,以对氧磷为例,建立了有机磷农药的荧光检测方法。该方法的线性关系良好,LOD为0.05 μg L-1,河水和自来水中的添加回收率为90-103%。本论文制备了不同的纳米材料,将其分别用于农药多残留的基质净化、邻苯二甲酸酯提取和有机磷农药的荧光检测,开发了新的样品前处理的净化剂、有机污染物提取方法和有机磷农药的检测方法。
[Abstract]:Pesticides and organic pollutants in the sample content is relatively low, but there are potential hazards to human and other organisms. The matrix of environmental sample is complex, so it is necessary to separate and enrich the target analyte from the complex matrix through the sample treatment process before the qualitative and quantitative analysis can be carried out. The existing sample pretreatment methods are time-consuming, cumbersome, and the commonly used detection methods usually need more expensive instruments, and the analysis cost is high and needs professional operation. Therefore, it is very important to develop simple, fast and cheap sample pretreatment and detection methods. Nanomaterials have a large specific surface area and unique optical properties, which can be used for pretreatment and detection of environmental samples. This thesis is divided into three parts. In the first part, the purification of graphene in pesticide multi-residue analysis was studied by using fruit and vegetable samples as substrate. Firstly, the graphene was characterized by photoelectron spectroscopy and Raman spectroscopy. Then, 17 kinds of pesticides were selected for GC-MS analysis to study the purification effect of graphene as a dispersive solid phase extraction adsorbent for carrot, grape, tomato and rape. The experimental results show that the recovery rate of the target pesticide is 92-120. Graphene has a good purification effect on all kinds of matrix, and its purification effect is better than that of graphitized carbon black. The second part: 15 phthalates were selected as target analytes to study the extraction of graphene to environmental pollutants in water. 15 phthalates were detected by GC-MS, the amount of graphene was measured, the adsorption solvent was desorbed. The adsorption time, desorption time and pH were optimized, and the method was applied to the analysis of water and sea water samples from 7 places in China. The experimental results show that under the optimized conditions, the recoveries of 15 phthalates in ultrapure water, river water and seawater are 71-117.The linear relationship of the method is good, and it can be used for the detection of practical samples. In the third part, the application of nanomaterials in organophosphorus pesticide detection was studied. The prepared MnO2 nanoparticles, carbon quantum dots and gold nanoparticles were characterized by TEM,UV-Vis and fluorescence spectra. Zeta potential. MnO2 nanoparticles can induce fluorescence quenching of fluorescein isothiocyanate (FITC) and the quenching effect will be restored with the addition of H202. H2O2 can be produced by the catalysis of ethylcholinesterase and cholinesterase. Based on the properties of organophosphorus pesticides inhibiting cholinesterase activity, a fluorescence sensing method for the detection of organophosphorus pesticides by FITC-MnO2 nanoparticles was established. The linear relationship of the method is good, the LOD is 1 渭 g / L ~ (-1), and the recovery rate of adding in river water and tap water is 89 ~ 108. Compared with organic fluorescent dyes, carbon quantum dots have low toxicity and good biocompatibility. Gold nanoparticles can quench the fluorescence of carbon quantum dots by (FRET) through fluorescence resonance energy transfer. The products of acetylcholine hydrolyzed by butyrylcholinesterase can lead to the aggregation of gold nanoparticles, which can restore the fluorescence of carbon quantum dots. Based on the properties of organophosphorus pesticides inhibiting butyrylcholinesterase activity, a fluorescence detection method for organophosphorus pesticides was established. The linear relationship of the method is good, the LOD is 0. 05 渭 g L ~ (-1), and the recovery rate in river water and tap water is 90-103. In this paper, different nanomaterials were prepared and used for the purification of multi-residue matrix, extraction of phthalate and fluorescence detection of organophosphorus pesticides, and a new purifying agent for sample pretreatment was developed. Extraction of organic pollutants and determination of organophosphorus pesticides.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X592;S481.8

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