【作者】 徐阳；

【导师】 丁兰；

【作者基本信息】 吉林大学 ， 分析化学， 2014， 博士

【摘要】 本文旨在对磁性功能材料作为新型的固相萃取剂在样品分离中的应用进行研究和探索，我们将磁性分离技术与传统的固相萃取技术结合，制备出多种功能性的磁性固相吸附材料，并将它们应用于复杂样品的预处理过程。主要研究内容如下：一、以Fe3O4为磁核，制备出核-壳结构的磁性强酸型阳离子交换树脂，将其应用于吸附鸡蛋中的三聚氰胺，随后用液相色谱串联质谱进行测定。先后对合成条件和树脂用量、萃取时间及淋洗、洗脱条件等影响萃取效率的参数进行了优化，并成功地将该方法应用到实际鸡蛋样品的测定。二、通过加入表面活性剂和采用双功能单体改进合成方法，制备得到形貌更佳、粒径分布更均匀、磁性更好的磁性强酸型阳离子交换树脂，用于对人体血浆中的尼古丁进行萃取和富集。考察了树脂的吸附容量和再生性能，检验了方法的稳定性，最后成功地将该方法应用到对随机抽取的人体血样中尼古丁的测定。三、制备了磁性多壁碳纳米管，用于吸附鸡蛋中的七种磺胺类抗生素。对磁性纳米管的合成条件和会影响磺胺回收率的萃取条件进行了优化，对产物的形貌、所含官能团和磁学性质等进行了表征，并考察了磁性碳纳米管的再生性能。同国家标准方法进行比对后证实，本方法具备更低基质效应和更高的灵敏度。四、采用悬浮聚合法，以Fe3O4为磁核，扑草净为模板分子制备了核-壳结构的磁性分子印迹聚合物。对磁性分子印迹聚合物形貌和磁性进行了表征；绘制了磁性分子印迹聚合物和磁性非分子印迹聚合物的吸附等温线并进行了Scatchard分析；完成了对方法选择性的评价。最后将方法应用于对多种蔬菜样品中三嗪类除草剂的检测。五、利用表面聚合原理，以Fe3O4为磁核，以磺胺对甲氧嘧啶和环丙沙星两种化合物为组合模板，制备了磁性组合模板表面分子印迹聚合物。对多项合成条件进行了考察和优化。对聚合物的形貌和磁性进行了表征，考察了方法的选择性，测试了相关的热力学数据，优化了各项萃取条件。最后，我们将该方法应用于环境水样中磺胺类和氟喹诺酮类的同时检测。更多还原

【Abstract】 Magnetic functional materials are those materials consisted of magnetic componentand non-magnetic functional component. On one hand, they have the same physicaland chemical properties as regular functional materials; on the other hand, they couldbe separated from the sample matrix easily due to their high magnetic responseperformance. In recent years, studies based on magnetic functional materials havebeen developed very fast in various scientific fields including materials, physics,chemistry and bioscience because of the many advantages they own. And thesematerials have already played important roles in areas such as catalyzing, materialscience, cellular segregation, drug delivery, enzyme immobilization andenvironmental conservation.Due to the super magnetic property of the magnetic functional materials, theycould have even better prospects in separation science. The main purpose of thisthesis is to develop new sample pretreatment methods and techniques that make useof the magnetic functional materials as adsorbents. Different types of these materialswere prepared in this study using hydrophobic Fe3O4magnetite as magneticallysusceptible component, and have been successfully applied to the pretreatmentprocedures of complex sample, followed by LC-MS/MS analysis. The main contentsand results of this thesis are as followed:1. Magnetic strong cation exchange (MSCX) resins with core-shell structure wereprepared using hydrophobic Fe3O4magnetite as magnetically susceptible component,styrene and divinylbenzene as polymeric matrix components, acetyl sulfonate as thesulphonation agent. The resins were successfully applied to the extraction ofmelamine (MEL) from egg samples. The extraction and enrichment procedures were fulfilled simultaneously by simply blending and stirring the sample, extraction solventand the MSCX resins. The MEL was extracted from the sample matrix, and thenadsorbed onto the resins directly through ion-exchange interaction. When theextraction was completed, the resins with adsorbed analyte were easily separated fromthe sample matrix by external magnetic field. The analyte eluted from the resins wasdetermined by LC-MS/MS. Parameters such as synthesis and extraction conditionsincluding Amount of MSCX resins, extraction time, washing and eluting conditionswere optimized. The proposed method was successfully applied to determine MEL ineggs obtained from different local markets. The limit of detection is2.6ng g-1, and therecoveries of MEL are in the range of77%–99%.2. The preparation method of the MSCX resins was modified by the addition ofsodium dodecyl sulfate into the reaction system as surface-active agent, also acrylicacid was chosen as co-monomers together with styrene. Therefore, the polymerizationtime was effectively shortened, the polymerization procedure was simplified as well.The MSCX resins obtained by the modified method not only had better configurationand particle size distribution, also could maintain high magnetic response though longtime sulfonation. They were applied as adsorbents for the extraction and enrichmentof trace amounts of nicotine from plasma samples followed by LC-MS/MSdetermination. The cation exchange capacity and regeneration property of the resinswere investigated, the stability test of the method was also carried out. Finally theproposed method was successfully applied to determine nicotine in human plasmaphlebotomized from ten male smokers.3. A simple and effective method based on magnetic separation has been developedfor the extraction of sulfonamides (SAs) from egg samples using magneticmultiwalled carbon nanotubes (MMWCNTs) as adsorbents. The MMWCNTs weresimply prepared by mixing FeCl3·6H2O with MWCNTs that had been previouslyoxidized. A variety of synthesis and extraction conditions, which could affect therecoveries of the SAs, were optimized. The configuration，functional groups andmagnetic property of the MMWCNTs were characterized by scanning electronmicroscopy, Fourier-transform infrared spectrometry and vibrating samplemagnetometer, respectively. Comparing with the China National Standard methodpublished in2007, the proposed method can provide lower matrix effect and higher sensitivity, the limit of detection of all seven SAs are below3.0ng g1. The testingresult obtained by the proposed method are very accurate dependable.4. Magnetic separation and molecularly imprinted technique were successfullycombined in this work. Magnetic molecularly imprinted polymers (MMIPs) withcore-shell structure were synthesized using Fe3O4magnetite as magneticallysusceptible component, prometryn as template molecule, methacrylic acid asfunctional monomer, ethylene glycol dimethacrylate as crosslinking agent andazodiisobutyronitrile as initiator. The produced MMIPs had both high selectivitytowards the target analytes and high magnetic response while applying magnetic field.They were then applied for the extraction of six triazine herbicides from vegetablesamples. The MMIPs were characterized by scanning electron microscopy andvibrating sample magnetometer. The adsorption isotherms of MMIPs and MNIPswere plotted according to the results obtained by static equilibrium adsorptionexperiment, and the corresponding Scatchard analysis was also performed. Theselectivity experiment was then carried out by comparing the difference between theMMIPs and MNIPs on the adsorption capacity of template molecule, structuralanalogues and reference compounds. Finally the method was applied to determinetriazine herbicides in various practical vegetable samples and the results werecompared with those obtained by the China National Standard method.5. Magnetic mixed-templates molecularly imprinted polymers(Fe3O4@SiO2@MIPs) were prepared using surface polymerization method. TheFe3O4@SiO2@MIPs were synthesized using Fe3O4magnetite as magneticallysusceptible component, both sulfametoxydiazine and ciprofloxacin as templatemolecules, methacrylic acid as functional monomer, ethylene glycol dimethacrylate ascrosslinking agent. Compered with the regular MMIPs, MMIPs prepared usingsurface polymerization have bigger specific surface area, and almost all the bindingsites are distributed on the surface of the polymers so that the template could beremoved more easily. Moreover, the efficiency of the adsorption and desorption oftarget analytes are significantly enhanced. In the discussion section, synthesisconditions such as amount of the Fe3O4magnetite, types and ratio of the two templatemolecules, type of functional monomer, also the ratio of templates, monomer andcross-linking agent, have been optimized. The Fe3O4@SiO2@MIPs were characterized,the selectivity experiment was completed, thermodynamic data was collected, and theextraction conditions were optimized. Finally, the method is applied to the simultaneous extraction of sulfonamides and fluoroquinolones from environmentalwater, limit of detection of the two species are3.0-4.7ng L1and4.1-6.1ng L1,respectively.更多还原