【作者】 王涎桦；

【导师】 万谦宏；

【作者基本信息】 天津大学 ， 应用化学， 2012， 博士

【摘要】 分析仪器的不断发展使食品中有害物质检测取得了巨大进步，然而样品预处理技术的不足常常会制约分析仪器检测的准确度和精密度。固相萃取在样品预处理技术中具有举足轻重的地位，但其存在选择性差的缺点，导致处理后的检测样品存在大量干扰成分。分子印迹聚合物是一类对目标分子具有特异性识别和选择性吸附的新型固相吸附材料，能有效降低基质干扰，在复杂样品预处理领域具有广泛应用前景。当前，大量化学物质通过各种途径进入到人类的食物中，其中包括饲料添加剂、农药、兽药、食品添加剂等，其中一些具有致癌、致畸、致突变作用,对人类的健康安全造成了严重的威胁。环丙氨嗪是一种三嗪类杀虫剂，其毒性虽较小，但在动物体内可代谢为三聚氰胺。人体摄入三聚氰胺会导致肾衰竭，甚至尿石症和膀胱癌，所以同时检测食品中的环丙氨嗪和三聚氰胺十分重要。二者同时检测方法很多，但是其样品预处理方法也存在选择性差、分析基质中存在大量干扰杂质的问题。因此本文以环丙氨嗪和三聚氰胺为检测模型，制备了环丙氨嗪分子印迹聚合物、准模板分子印迹聚合物、亲水疏水平衡分子印迹聚合物和磁性分子印迹聚合物，并将其应用于复杂样品中环丙氨嗪和三聚氰胺的连续定量检测。具体研究成果如下所述：（1）合成对环丙氨嗪和三聚氰胺均具有特异选择性的环丙氨嗪分子印迹聚合物，利用红外光谱、扫描电镜、电导滴定羧基等表征其性质，将其作为固相萃取材料，首次用于同时富集、分离实际样品中环丙氨嗪和三聚氰胺。用于湖水样品检测时，两者平均回收率为90.7%-98.0%；用于牛奶样品时，平均回收率为86.3%-91.5%。结果显示，与传统的固相萃取材料相比，在同时富集、分离环丙氨嗪和三聚氰胺的过程中，本研究中的环丙氨嗪分子印迹聚合物能有效降低基质干扰，提高检测环丙氨嗪和三聚氰胺的准确度。（2）环丙氨嗪分子印迹聚合物在用于检测环丙氨嗪时，存在模板泄露的风险，为了避免其对检测结果的影响，我们选择合理的准模板，制备对环丙氨嗪和三聚氰胺均具有特异识别能力的准模板分子印迹聚合物。以其作为吸附材料制备固相萃取柱，优化固相萃取过程，与高效液相色谱联用，检测食品中的环丙氨嗪和三聚氰胺。在标准添加实验中，二者的回收率为89.8%-98.8%。结果显示，与环丙氨嗪分子印迹聚合物相比，准模板分子印迹聚合物作为固相萃取材料不仅能有效排除基质对检测结果的干扰，还能完全避免分子泄露引起的假阳性结果。同时，准模板分子印迹聚合物可大量生产，易于推广使用。（3）上述准模板分子印迹聚合物以甲苯为致孔剂制备，在水溶液中对靶标分子识别能力差，为了增加分子印迹聚合物在水中的识别能力，引入甲基丙烯酸缩水甘油酯作为共聚单体，聚合后开环，制备对环丙氨嗪和三聚氰胺具有特异选择性的亲水疏水平衡分子印迹聚合物。将其作为固相萃取材料，与高效液相色谱联用，检测实际样品中的环丙氨嗪和三聚氰胺。通过湖水中的标准添加实验可知，在添加浓度为0.1μg/mL时，亲水疏水平衡分子印迹聚合物萃取环丙氨嗪和三聚氰胺的回收率分别比（2）中的方法高1.5%和3.6%，与（1）中的方法基本一致。证明亲水疏水平衡分子印迹聚合物更适合萃取水溶液中的环丙氨嗪和三聚氰胺，且不存在模板泄露的风险。（4）为了实现检测的快速化、自动化和高通量，在（2）的基础上，我们制备了对环丙氨嗪和三聚氰胺均具有特异识别能力的球形磁性分子印迹聚合物。利用振动样品磁强计、电镜、红外等手段表征了制备的磁性准模板分子印迹聚合物。并将此种磁性分子印迹聚合物用于磁性分子印迹固相萃取，优化萃取条件，与高效液相色谱联用，检测鸡蛋和牛奶中的环丙氨嗪和三聚氰胺。标准添加实验中，二者的平均回收率为71.86%-80.57%。与上述三种分子印迹固相萃取方法相比，磁性分子印迹固相萃取可明显缩短分析时间，且易高通量、微型化、自动化。更多还原

【Abstract】 In recent years, a huge progress of determination of harmful substances in foodhas achieved with the development of analytical instrumentation. Sample pretreatment,as one of the critical procedures in quantitative analysis, directly influences theprecision and accuracy of the analytical method. However, large amounts of matrixinterferences being extracted simultaneously with the target analyte, known as thematrix-effect, leads to poor selectivity of the conventional solid phase extraction (SPE)technique, as well as low separation and enrichment efficiency. Molecularly imprintedpolymers can specifically recognize the imprinted molecules. When acting as SPEmaterial, molecularly imprinted polymers are selectively capable of enrich targetmolecules on the matrix without matrix interference, which makes it a potentialmaterial in the field of pretreatment of complex sample.Recently, a large number of chemicals were brought into human foods, includingfeed additives, pesticides, veterinary drugs and food additives. Some of them werecarcinogenic, teratogenic and mutagenic, which was a grave threat to public health.Cyromazine, which possesses less toxicity, is an insect growth regulator used for flycontrol in crop production and protecting animal feed by inhibiting insects growing. Itcan also be metabolized to melamine through environmental degradation viadealkylation reaction in both plants and animals. Melamine would lead tocrystallization and subsequent renal failure and even cause urolithiasis and bladdercancer by forming insoluble complexes with cyanuric acid in the kidneys. So it is veryimportant to determine cyromazine and melamine simultaneously. There are manymethods for their determination, but they all involve in poor selectivity and a largenumber of interfering substance. In the thesis, some molecularly imprinted polymerfor cyromazine and melamine were prepared and used to determine cyromazine andmelamine in complex sample. The details of this thesis are outlined as follows:1) Cyromazine imprinted polymers were prepared, and used as SPE materials.The combination of cyromazine imprinted polymer solid-phase extraction with highperformance liquid chromatography has been developed to isolate, enrich anddetermine cyromazine and its metabolic melamine in some samples. In lake watersamples, good recoveries of cyromazine and melamine were obtained as 98.0%-90.7%; in the milk samples, good recoveries were obtained as86.3%-91.5%.These results show that cyromazine imprinted polymer could effectively reduce thematrix interference and improve the accuracy in determining cyromazine andmelamine.2) To avoid the possible risk of template leakage for using cyromazine imprintedpolymer to determine cyromazine and melamine, psuedo template molecularlyimprinted polymers for cyromazine and melamine were firstly prepared, The resultingpseudo molecularly imprinted polymers were used as a solid-phase extraction materialto enrich cyromazine and melamine, and different protocols were optimized. Thecombination of pseudo template molecularly imprinted solid-phase extraction withhigh performance liquid chromatography has been developed to determinecyromazine and melamine in egg and milk samples. In the standard addingexperiment, the mean recoveries ranged from89.80to98.14%for cyromazine andmelamine, respectively. Compared to cyromazine imprinted polymer, pseudo templatemolecularly imprinted polymers could effectively reduce the matrix interference, butalso completely avoid the possible risk of template leakage. And it would be easy tomass produce and extende3) The above pseudo template molecularly imprinted polymers were prepared byusing toluene as a porogen, so it had a poor affiniting and selectivity in water solution.For this reason, hydrophilic-hydrophobic balance molecules imprinted polymers werefirstly prepared with glycidilmethacrylate as co-monomer. In water solutions, thepolymer had more excellent affinity and selectivity for cyromazine and melamine thanpseudo molecularly imprinted polymers. The hydrophilic-hydrophobic balancemolecules imprinted polymers were used as a solid-phase extraction material to enrichcyromazine and melamine in lake water. When cyromazine and melamine were allspiked at0.1μg/g, the recoveries of hydrophilic-hydrophobic balance moleculesimprinted solid-phase extraction were improved1.5%and3.6%compared topseudo template molecules imprinted solid-phase extraction respectively.Hydrophilic-hydrophobic balance molecules imprinted solid-phase was more suitablefor extraction cyromazine and melamine in water and could avoid the possible risk oftemplate leakage.4) In order to realize quickly high-throughput and automated detection, magneticmolecularly imprinted polymers for cyromazine and melamine were prepared bysimple suspension polymerization. It was characterized by VSM, TEM, FT-IR and used as a solid-phase extraction material. A method based on molecularly imprintedsolid-phase extraction assisted by magnetic separation was developed to extractcyromazine and melamine from egg and milk samples. When cyromazine andmelamine were at different fortified concentrations, the mean recoveries ranged from71.86%to80.56%. Compared to above three kinds of molecularly imprintedpolymers, magnetic molecularly imprinted polymers could shorten the analytical timeand was suitable for high-throughput selection, miniaturization and automation.更多还原