孔雀石绿分子印迹膜的制备、性能及应用研究

发布时间：2018-08-28 08:34

【摘要】：孔雀石绿(malachite green,MG)是一种有毒的三苯甲烷类化合物,在水生物体内的代谢产物为隐性孔雀石绿(leucomalachite green,LMG),其毒性比MG更强。MG对于预防和治疗水产品的疾病具有较好的效果,且价格低廉,是最常见的渔药之一。近年来,MG残留问题屡屡被曝光,严重威胁到人类健康及水产品贸易,许多国家先后对孔雀石绿颁布了禁用公告,禁止其在可食用动物中使用。本研究尝试以玻璃纤维膜为底材,以目标物结构类似物为替代模板分子,采用表面分子印迹法合成孔雀石绿分子印迹膜(malachite green-molecularly imprinted membranes,MG-MIM_s)。既解决了传统分子印迹法“模板泄露”和印迹位点“包埋”过深等问题,又将分子印迹技术与膜分离技术相结合,使识别位点位于聚合物表面,并加快了MGMIM_s的传质速率。首先,本研究对MG-MIMs的合成条件进行了优化,最终选择以疏水型玻璃纤维膜为聚合底材,碱性紫(methyl violet,MV)为替代模板分子,4-乙烯基苯甲酸为功能单体,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,乙腈(ACN)为溶剂,采用替代模板分子:功能单体:交联剂的摩尔比为1:4:24,制备MG-MIMs。采用扫描电子显微镜(SEM)、比表面仪(BET)、紫外-可见分光光度计(UV-VIS)、傅里叶转换红外光谱仪(FT-IR)及同步热分析仪(TGA/DSC)等表征手段,研究MG-MIM_s的微观形貌、吸附能力、分子结构及热稳定性。结果表明,大部分的功能单体与交联剂发生了交联反应,MG-MIM_s的表面蓬松,呈多孔、疏松结构,且在使用温度范围内具有良好的热稳定性。其次,本研究对MG-MIM_s的萃取条件进行了优化。结果表明,最佳萃取条件为:萃取溶剂选择30mL20%乙腈/PBS缓冲盐溶液(V%,pH=5,盐浓度为1%),在60次/min的振荡速率下振荡萃取20min,再用1mL10%乙酸/乙腈(V%)溶液洗脱目标物。在最佳制备条件和萃取条件下,深入研究了MG-MIM_s的吸附性能。结果表明,MG-MIM_s能在20min达到吸附平衡,对MG和LMG的饱和吸附量分别为24.25 ng·cm-2和13.40ngcm-2,最大印迹因子分别为2.41和3.20;同时,MG-MIM_s具有较强的耐酸、耐碱、耐有机溶剂的性质,在重复使用次数为5次内时,其对目标物的特异识别能力良好,吸附容量基本稳定。最后,本研究对方法进行了评估。结果表明,MG和LMG的线性范围为0-50μg·L-1,线性相关系数均大于0.9991。空白鱼样和空白虾样的加标回收率分别为76.31%-93.26%和79.53%-96.26%,RSD分别为0.78%-2.33%和0.73%-3.72%,MG和LMG的检测限(n=3)分别为0.005μgkg-1和0.02μg·kg-1,定量限(n=10)分别为0.02μgkg-1和0.05μgkg-1。测定结果表明各项指标均符合孔雀石绿残留分析质量控制限量要求。将分子印迹技术与快速检测技术相结合,检测限为1μgkg-1,符合国家对孔雀石绿的禁用要求,且适用于实际样品的检测。本研究将分子印迹技术与快速检测技术相结合,利用分子印迹聚合物表面的特异识别位点,大大缩短了样品前处理时间,具有简单、快速、抗基质干扰能力强、选择性高等优点,有效改善了现有快速检测技术缺乏合适前处理技术而造成的检测结果不准确的问题,可望实现与快速检测技术联用,为复杂基质中痕量MG的检测提供一个新方法,具有一定的理论意义和实际应用价值。
[Abstract]:Malachite green (MG) is a toxic triphenylmethane compound. Its metabolite in aquatic organisms is leucomalachite green (LMG), which is more toxic than MG. MG is one of the most common fishery drugs for preventing and treating diseases of aquatic products with good effect and low cost. Many countries have banned malachite green from being used in edible animals. In this study, Malachite was synthesized by surface molecular imprinting with glass fiber membrane as substrate and structural analogue as template molecule instead of template molecule. Green-molecularly imprinted membranes (MG-MIM_s) not only solve the problems of "template leak" and "embedding" of imprinted sites by traditional molecular imprinting method, but also combine molecular imprinting technology with membrane separation technology to locate recognition sites on the polymer surface and accelerate the mass transfer rate of MGMIM_s. Firstly, the synthesis conditions of MG-MIMs were optimized. At last, hydrophobic glass fiber membrane was used as polymeric substrate, methyl violet (MV) as template molecule, 4-vinylbenzoic acid as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linking agent, azodiisobutyronitrile (AIBN) as initiator, acetonitrile (ACN) as soluble. MG-MIM s were prepared by substituting template molecule: functional monomer: the molar ratio of crosslinking agent was 1:4:24. The morphology and adsorption energy of MG-MIM s were studied by scanning electron microscopy (SEM), surface area measurement (BET), ultraviolet-visible spectrophotometer (UV-VIS), Fourier transform infrared spectroscopy (FT-IR) and synchronous thermal analysis (TGA/DSC). The results showed that most of the functional monomers had crosslinking reaction with the crosslinking agent. The surface of MG-MIM_s was fluffy, porous and porous, and had good thermal stability in the temperature range. Secondly, the extraction conditions of MG-MIM_s were optimized. 30 mL 20% acetonitrile/PBS buffer solution (V%, pH = 5, salt concentration 1%) was selected as the extraction solvent. The target compound was extracted for 20 minutes at 60 times/min oscillation rate, and then eluted with 1 mL 10% acetic acid/acetonitrile (V%) solution. Under the optimum preparation conditions and extraction conditions, the adsorption properties of MG-MIM_s were studied in depth. The saturated adsorption capacity of MG and LMG were 24.25 ng cm-2 and 13.40 ng cm-2, respectively, and the maximum imprinting factor was 2.41 and 3.20, respectively. Meanwhile, MG-MIM_s had strong acid, alkali and organic solvent resistance, and its specific recognition ability to target was good and adsorption capacity was basically stable within 5 reuse times. The results showed that the linear ranges of MG and LMG were 0-50 and 0.9991 respectively. The recovery rates of blank fish and shrimp samples were 76.31% - 93.26% and 79.53% - 96.26%, RSD were 0.78% - 2.33% and 0.73% - 3.72% respectively. The detection limits of MG and LMG (n = 3) were 0.005 and 0.02 UG (- 1) respectively. The quantitative limits (n=10) were 0.02 and 0.05 UG kg-1 respectively. The results showed that all the indexes met the requirements of quality control limits for malachite green residue analysis. The detection limit was 1 ug kg-1 by combining molecular imprinting technique with rapid detection technique, which met the national banned requirements for malachite green and was suitable for the detection of real samples. The combination of molecular imprinting technology and rapid detection technology, using the specific recognition sites on the surface of molecularly imprinted polymers, greatly shortens the sample pretreatment time, has the advantages of simplicity, rapidity, strong anti-matrix interference ability, high selectivity, and effectively improves the detection knot caused by the lack of appropriate pretreatment technology in the existing rapid detection technology. If the results are not accurate, it is expected to be combined with rapid detection technology to provide a new method for the detection of trace MG in complex matrix, which has certain theoretical significance and practical application value.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S948;O631.3

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