【作者】 于春梅；

【导师】 乔利珍；

【作者基本信息】 大连理工大学 ， 分析化学， 2021， 硕士

【摘要】 现代工业的快速发展,产生了大量污染物,给环境带来极大压力,一些污染物会通过环境接触或食物链等方式对人类健康产生巨大影响,因此,对环境中污染物进行检测和控制十分必要。但是在实际样品的检测过程中,由于基质复杂和目标分析物的浓度较小,直接进样往往检测不到或极大影响仪器的准确性。因此,需要发展新型材料对样品进行仪器检测前的预处理,去除基质影响,富集目标分析物,使得富集过程高效简单。针对环境中存在的污染物,利用磁固相萃取分离方便、省时、高效等特点,本论文设计了新的磁固相萃取材料,对复杂样品中的目标分析物进行富集净化。基于此,本论文主要包括以下三部分工作:（1）制备了一种新型胍盐离子液体[di Pr NH₂TMG]Cl（GIL）,利用聚乙烯亚胺作为中间桥梁,通过共价键修饰将得到的胺基功能化胍盐离子液体固定于包覆了二氧化硅的四氧化三铁（Fe₃O₄@n SiO₂）表面,得到Fe₃O₄@n SiO₂-GIL磁性纳米材料。制备的Fe₃O₄@n SiO₂-GIL纳米材料作为磁固相萃取的吸附材料对水中的多环芳烃（PAHs）具有良好的富集效率,最低检测限（LODs）可以达到0.05-0.1 ng?m L^-1,加标回收率在80-120%之间,线性相关系数（r²）在0.996以上。本方法与高效液相色谱-紫外检测（HPLC-UV）结合使用,可用于环境水样中污染物如PAHs的有效提取和检测。（2）开发了一种三维（3D）花状的磁性SnS₂复合材料Fe₃O₄@n SiO₂-SnS₂用于自来水、牛奶和蜂蜜中磺酰胺类抗生素（SAs）的萃取。相比于二维（2D）构型,3D结构的SnS₂材料更加稳定,有利于暴露更多活性位点,结合磁性材料的优点使得萃取分离过程简单高效。对磁固相萃取条件进行优化,结果显示,采用制备的Fe₃O₄@n SiO₂-SnS₂材料,预处理操作简单便捷,萃取和解吸可以在2 min内达到平衡。结合HPLC-UV,本方法对SAs的LODs可以达到0.025 ng?m L^-1,在0.1-200 ng?m L^-1线性范围内r²在0.9964以上,在牛奶和蜂蜜等复杂样品中的加标回收率在80-120%之间,说明所制备的Fe₃O₄@n SiO₂-SnS₂萃取材料对于SAs的萃取具有很大的潜力。（3）为了增加材料的比表面积,提高萃取效率,在第一部分工作的基础上,我们在Fe₃O₄@n SiO₂的非介孔SiO₂表面,继续包覆一层介孔SiO₂,利用胺基功能化的GIL、戊二醛和富胺基的碳点之间的反应,进行表面修饰,得到的材料用于酞酸酯增塑剂的富集测定。与非介孔Fe₃O₄@n SiO₂表面直接修饰得到的材料相比,修饰后的Fe₃O₄@n SiO₂@m SiO₂介孔材料的比表面积和吸附容量更大,萃取效率更高。更多还原

【Abstract】 The rapid development of modern industry has produced a large number of pollutants and brought great pressure to the environment.Pollutants would impose a huge impact on human health through environmental contact or the food chain,and it is very important to detect and control the concentration of pollutants in the environment.However,due to the complexity of the matrix and the low concentration of the target analytes,direct injection of sample solution for determination is often infeasible or greatly affects the accuracy of the instrument.Therefore,it is necessary to develop new materials for efficient,simple and selective pretreating samples before instrument detection to remove matrix effects and enrich target analytes.Aiming at the pollutants in the environment and taking advantages of the characteristics of magnetic solid-phase extraction such as convenient,time-saving and high-efficiency,this paper is devoted to the design and development of new magnetic solid-phase extraction materials to enrich and purify the target analytes in complex samples.The thesis mainly includes the following three parts:（1）A new guanidinium ionic liquid N,N,N’,N’-tetramethyl-N",N"-2-（3-aminopropyl）chloride[di Pr NH₂TMG]Cl（GIL）was prepared and modified covalently onto the surface of Fe₃O₄@n SiO₂ particles using polyethyleneimine as a linkage bridge The obtained Fe₃O₄@n SiO₂-GIL nanoparticles were used as the adsorption materials for magnetic solid phase extraction of polycyclic aromatic hydrocarbons（PAHs）in water and presented good enrichment efficiency.The limits of detection（LODs）were 0.05-0.1 ng?m L^-1,the recoveries of spiked samples were between 80-120%and the linear correlation coefficient（r²）was above0.996.In combination with high-performance liquid chromatography-ultraviolet detection（HPLC-UV）,the proposed method can be used for the effective extraction and determination of pollutants such as PAHs in environmental water samples.（2）Three-dimensional（3D）and flower-like magnetic SnS₂ composites Fe₃O₄@n SiO₂-SnS₂ were prepared and used to extract sulfonamide antibiotics（SAs）in tap water,milk and honey.Compared with 2D materials,the 3D SnS₂ materials were more stable and could expose more active sites.Combined with magnetic materials,the extraction and separation process were simple and efficient.The magnetic solid phase extraction conditions were optimized,and the results showed that the extraction and desorption could reach equilibrium within 2 minutes using the prepared Fe₃O₄@n SiO₂-SnS₂ materials.Combined with HPLC-UV,the LODs were 0.025 ng?m L^-1,and the r² values were above 0.9964 in the concentration range of 0.1-200 ng?m L^-1.The recoveries were acceptable for spiked real samples at three concentrations levels,ranging from 80%to 120%for milk and honey,and the RSDs were less than 13%.The results indicated that the prepared Fe₃O₄@n SiO₂-SnS₂materials had a great potential for the extraction of SAs.（3）In order to increase the specific surface area and improve extraction efficiency,a mesoporous SiO₂ layer was modified on the non-mesoporous SiO₂ surface of Fe₃O₄@n SiO₂.The amine functionalized GIL and carbon dots reacted with glutaric acid and modified on the surface of mesoporous materials,and the obtained materials were used for the enrichment of phthalate esters.Compared with non-mesoporous Fe₃O₄@n SiO₂,the specific surface area and adsorption capacity of Fe₃O₄@n SiO₂@m SiO₂ materials were larger,and higher extraction efficiency can be obtained.更多还原