金属有机骨架材料在多环芳烃的环境水样分析中的应用

发布时间：2018-07-01 21:21

  本文选题：样品前处理 + 固相萃取　； 参考：《湖南大学》2015年硕士论文

【摘要】：多环芳烃由于其稳定的结构而长期存在于我们的环境中,能够引起生物体的DNA损伤和它带来的致畸、致癌、致突变作用。因此这类化合物已引起广泛关注并被认证为最重要的一类持久性有机污染物,开发有效的分析检测方法是十分有必要的。但是带强疏水基团的多环芳烃在环境样品中往往是痕量存在的,而且环境样品的基质往往都很复杂,其对目标物的检测干扰很严重。因此不能对多环芳烃进行直接检测,实际样品进样前的预处理非常重要。目前,多种样品预处理技术已被开发,其中,固相萃取因具有消耗有机溶剂少、回收率高、操作简便等优点,备受科学研究者的关注。本工作重点在于开发新型固相萃取吸附剂,用于富集浓缩环境水样中的多环芳烃,并与高效液相色谱-荧光检测联用进行分析检测。研究内容如下:1.室温下,通过简单的磁力搅拌合成出粒径均一、对水稳定的微米级类沸石咪唑酯骨架材料ZIF-7,建立一种基于该种材料的固相萃取方法,联合HPLC-FLD应用于环境水样中多环芳烃的分析。这种材料原料易得、合成简便且对环境友好,通过优化一些实验条件,新方法对七种多环芳烃的检测限在0.13-2.66 ng L-1范围内,相对标准偏差RSD均在10%以内,展现了良好的重现性。在加入标准混合物的环境样品中,PAHs的回收率为78.8-90.3%,RSD≤9.4。2.利用相同的原料,在不同的有机溶剂中合成出两种拓扑结构不同的类沸石咪唑酯骨架材料ZIF-7和ZIF-11。通过傅里叶红外光谱、X射线衍射、扫描电镜以及接触角测量仪等表征,确定了两种材料成功合成且适用于固相萃取。经过比较,相同条件下,ZIF-11对多环芳烃的萃取效果比ZIF-7更好。因而,我们选择ZIF-11晶体作为吸附剂建立固相萃取的方法,用于环境水样中多环芳烃的分析。通过优化各种可能影响萃取的因素,包括萃取时间、洗脱溶剂、洗脱溶剂体积、有机改性剂的量和盐浓度,在最佳条件下水样中多环芳烃的回收率在82.4%至112.7%之间,相对标准偏差小于9%。3.室温下用一锅法合成了核壳结构的纳米-微米硅球,以此为支持材料,在其表面修饰了氨基后,用溶剂热法在其表面原位生长纳米Ui O-66。并以此复合材料为吸附剂建立新的固相萃取方法,用于环境水样中多环芳烃的前处理,通过HPLC-FLD进行检测。通过优化吸附剂的用量、有机改性剂的种类及用量、萃取时间和盐浓度,在最佳条件下,水样中多环芳烃的检测限在0.04-0.40 ng L-1范围内,回收率为88.0-105.1%,相对标准偏差小于7%。
[Abstract]:Polycyclic aromatic hydrocarbons (PAHs) exist in our environment for a long time because of their stable structure, which can cause DNA damage and teratogenic, carcinogenic and mutagenic effects of PAHs. Therefore, these compounds have attracted widespread attention and have been recognized as the most important class of persistent organic pollutants. It is necessary to develop an effective analytical method for detection of these compounds. However, polycyclic aromatic hydrocarbons (PAHs) with strong hydrophobic groups often exist in trace amounts in environmental samples, and the matrix of environmental samples is often very complex. Therefore, PAHs can not be directly detected, and the pretreatment of actual samples before injection is very important. At present, a variety of sample pretreatment techniques have been developed. Among them, solid phase extraction (SPE) has attracted the attention of scientific researchers for its advantages of less organic solvent consumption, high recovery rate and easy operation. This work focuses on the development of a novel solid phase extraction adsorbent for the enrichment of PAHs in environmental water samples and the analysis and detection of PAHs with high performance liquid chromatography-fluorescence detection. The research is as follows: 1. At room temperature, a homogeneous particle size was synthesized by simple magnetic stirring. A solid phase extraction method based on ZIF-7 was established, and the HPLC-FLD was used in the analysis of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. This material is easy to obtain, easy to synthesize and environmentally friendly. By optimizing some experimental conditions, the detection limit of the new method for seven PAHs is within 0.13-2.66 ng L-1, and the relative standard deviation (RSD) is within 10%, showing a good reproducibility. The recoveries of PAHs in environmental samples with standard mixtures were 78.8-90.3 and RSD 鈮，

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