分子印迹-基质固相分散快速分离分析辣椒制品中的苏丹红

以纳米SiO2为载体,苏丹红IV为模版分子,甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,采用表面印迹法制备分子印迹物聚合物。对该聚合物进行了吸附等温线的测定以及Scatchard分析,结果表明分子印迹聚合物对苏丹红IV有两种结合方式,计算得到的最大表观吸附量(Qmax)和平衡离解常数(Kd)分别为:Qmax1=0.8306mg/g,Kd1=4.760mg/L;Qmax2=4.146mg/g,Kd2=112.4mg/L。进行了吸附动力学的测定,结果显示该聚合物对苏丹红IV的吸附符合准二级动力学模型。最后应用该聚合物进行基质固相分散萃取辣椒制品中的苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ,最佳实验条件为:聚合物与样品的用量比1∶1,研磨时间8min,洗脱剂为4mL 5%乙酸乙醇溶液。该方法兼备了分子印迹技术的选择性和基质固相分散技术的快速分离性。     

虚拟模板分子印迹固相萃取-高效液相色谱法检测食品中联苯三唑醇与烯唑醇

利用虚拟模板分子印迹固相萃取技术对食品中的联苯三唑醇与烯唑醇进行分离富集,并建立高效液相色谱检测方法。以腈菌唑为模板分子,丙烯酰胺（AM）为功能单体,EDMA为交联剂,乙腈为致孔剂,采用本体聚合法制备得到了腈菌唑分子印迹聚合物（MMIP）,以此聚合物为固相萃取剂,制备固相萃取柱,对食品中联苯三唑醇和烯唑醇进行分离富集,并采用高效液相色谱法测定其在食品中的残留。采用C18色谱柱分离,以甲醇-水（体积比为90：10）溶液为流动相,紫外检测波长为210 nm,外标法定量。结果表明,联苯三唑醇和烯唑醇的平均回收率分别为89.40~90.88%和81.37~83.26%,RSD分别为1.08~2.04%和1.29~2.52%,检测限均为0.20 μg/g。此聚合物对两种杀菌剂具有良好的吸附能力,拟模板分子印迹固相萃取技术可以用于这两种杀菌剂的分离检测。     

双酚A环氧衍生物分子印迹聚合物的制备 及其吸附性能研究

目的 制备双酚A环氧衍生物的分子印迹聚合物。方法 采用沉淀聚合法, 以双酚A(bisphenol A, BPA)和双酚A二环氧甘油(bisphenol A diglycidyl ether, BADGE)为双模板分子, α-甲基丙烯酸(methacrylic acid, MAA)为功能单体, 三羟甲基丙烷三甲基丙烯酸酯(trimethylolpropane trim ethacrylate, TRIM)为交联剂, 偶氮二异丁腈(azodiisobutyronitrile, AIBN)为引发剂, 合成了一种高选择性的分子印迹聚合物, 运用扫描电镜、红外光谱分析等手段对其形貌、物理特征进行了表征, 同时进行了聚合物的静态吸附与动态吸附性能研究。结果 合成的分子印迹聚合物(molecularly imprinted polymers, MIPs)对10 种化合物的最大平衡吸附量为18.12~27.00 mg/g, 对10种化合物的吸附略有区别, 但差异不大, 而非印迹聚合物(non-imprinted polymers, NIPs)则对10种化合物的吸附量为7.10~10.73 mg/g, 说明NIPs吸附是由于存在物理吸附。结论 10种目标化合物在MIPs上均有吸附, 能够应用于分子印迹-固相萃取-高效液相色谱检测方法的建立。     

双酚A环氧衍生物分子印迹聚合物的制备及其吸附性能研究

目的制备双酚A环氧衍生物的分子印迹聚合物。方法采用沉淀聚合法,以双酚A(bisphenol A,BPA)和双酚A二环氧甘油(bisphenol A diglycidyl ether,BADGE)为双模板分子,α-甲基丙烯酸(methacrylic acid,MAA)为功能单体,三羟甲基丙烷三甲基丙烯酸酯(trimethylolpropane trim ethacrylate,TRIM)为交联剂,偶氮二异丁腈(azodiisobutyronitrile,AIBN)为引发剂,合成了一种高选择性的分子印迹聚合物,运用扫描电镜、红外光谱分析等手段对其形貌、物理特征进行了表征,同时进行了聚合物的静态吸附与动态吸附性能研究。结果合成的分子印迹聚合物(molecularly imprinted polymers,MIPs)对10种化合物的最大平衡吸附量为18.12~27.00mg/g,对10种化合物的吸附略有区别,但差异不大,而非印迹聚合物(non-imprinted polymers,NIPs)则对10种化合物的吸附量为7.10~10.73 mg/g,说明NIPs吸附是由于存在物理吸附。结论 10种目标化合物在MIPs上均有吸附,能够应用于分子印迹-固相萃取-高效液相色谱检测方法的建立。     

花椒麻味物质分子印迹聚合物的制备及吸附特性

为实现对花椒麻味物质经济高效的纯化制备,本实验采用分子印迹技术,以甲基丙烯酸为功能单体,花椒麻味物质为模板分子,合成对花椒麻味物质具有特异性识别和吸附能力的分子印迹聚合物(molecularly imprinted polymers,MIPs),并用MIPs制成固相萃取柱用于分离纯化花椒油树脂中的花椒麻味物质。吸附动力学实验结果显示,MIPs与花椒麻味物质接触约12 h后就达到吸附平衡,对花椒麻味物质识别因子α达到3.05;等温吸附实验表明,MIPs对花椒麻味物质的吸附量高于空白聚合物,在吸附过程中模板分子花椒麻味物质与MIPs形成两种结合位点,两种结合位点的解离常数分别为1.172×10~(-2) mg/m L和3.585×10~(-2) mg/m L,对花椒麻味物质最大表观吸附量分别为11.133 mg/g和15.802 mg/g;固相萃取实验表明,该固相萃取柱可以分离出相对纯度为94.09%的花椒麻味物质。     

花椒麻味物质分子印迹固相萃取柱的制备及其应用

以α-(羟基)-山椒素分子结构类似物为模板分子、2-乙烯基吡啶(2-vinylpyridine,2-Vpy)为功能单体、二甲基丙烯酸乙二醇酯(ethyleneglycol dimethacrylate,EDMA)为交联剂,按1∶4∶20的摩尔比合成了花椒麻味物质硅胶表面分子印迹聚合物,并以合成的硅胶表面分子印迹聚合物为固相萃取柱填料,制备了花椒麻味物质分子印迹固相萃取柱,确定了该固相萃取柱的最佳上样溶剂、淋洗溶剂及洗脱溶剂,用此固相萃取柱对花椒油树脂中的花椒麻味物质进行分离纯化。结果表明,该固相萃取柱对花椒麻味物质表现出优异的特异性吸附效果,可以分离纯化出相对纯度为93.66%的花椒麻味物质。     

罗丹明B表面分子印迹聚合物的制备及吸附性能

采用分子印迹技术以罗丹明B为模板分子,硅胶为载体,偶氮二异丁腈为引发剂,二甲基丙烯酸乙二醇酯为交联剂,通过悬浮聚合法合成了三种罗丹明B表面分子印迹聚合物。考察了影响该三种表面印迹聚合物对罗丹明B的吸附能力的因素、吸附等温线和动力学。结果表明,三种表面分子印迹聚合物对罗丹明B均具有较高的吸附效果,且三种表面分子印迹聚合物对罗丹明B的等温吸附过程均服从Langmuir方程,饱和吸附量分别为101.731,91.071和70.572 mg/g;动力学研究表明该吸附过程遵从准二级动力学方程,吸附速率分为0.012 1, 0.018 5和0.024 9g·mg~(-1)·min~(-1)。     

烘焙程度对小粒咖啡5-羟甲基糠醛生成的影响

基于液液-分散固相萃取净化和高效液相色谱仪建立烘焙咖啡中5-羟甲基糠醛定量测定方法.采用1％乙酸-乙腈溶液作为提取溶剂,3.0 g氯化钠+1.0 g乙酸钠为盐析剂,50 mg C18粉+20 mg N-丙基乙二胺+200 mg无水硫镁酸为分散固相萃取净化剂.以Shiseido CAPCELL PAK MG C18色谱柱...     

白藜芦醇分子印迹聚合物的应用及性能研究

采用分子印迹技术以白黎芦醇为模板分子,选择丙烯酰胺作为白藜芦醇印迹聚合物的功能单体,氯仿和四氢呋喃的混合溶液作为印迹聚合物合成溶剂,制备了白黎芦醇分子印迹聚合物,考察了分子印迹聚合物的吸附性能、选择性能以及固相萃取性能。优化分子印迹固相萃取的萃取条件,选择30%(体积分数)的乙醇-水溶液5 m L作为上样溶液,选择40%(体积分数)的乙醇-水溶液作为淋洗液、80%(体积分数)的乙醇-水溶液作为洗脱液。     

对位红新型功能材料的制备及其选择吸附性能研究

采用表面分子印迹和溶胶-凝胶技术,以对位红作为模板分子,离子液体作为辅助模板,二氧化硅微球为载体,制备对对位红具有高选择性的分子印迹硅球.红外分析表明,APTES已连接到活化硅球的表面并与对位红发生反应,生成印迹聚合物.通过静态吸附和竞争试验,对印迹聚合物硅球的选择吸附性能进行评价.结果表明:印迹聚合物对对位红的吸附容量为13.49mg/g,明显高于非印迹聚合物6.41 mg/g,而印迹聚合物和非印迹聚合物对苏丹红Ⅰ～Ⅳ号的吸附容量相差很小.对位红在印迹聚合物中的分配系数为145.0,明显高于其在非印迹聚合物中的分配系数59.8.本试验中制备的印迹聚合物具有良好的选择吸附性能.     

沙拉沙星分子印迹聚合物的制备及其性能研究

以沙拉沙星为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用本体聚合制备沙拉沙星的分子印迹聚合物。通过振荡吸附实验对模板分子和功能单体的比例进行优化。印迹聚合物和空白聚合物的等温吸附线表明,印迹聚合物形成的孔穴对沙拉沙星的吸附量高于空白聚合物。在吸附过程中模板分子沙拉沙星与印迹聚合物形成两种结合位点,两种结合位点的解离常数分别为0.321μg/mL和1.577μg/mL,对沙拉沙星最大表观吸附量分别为1.249mg/g和3.222mg/g。吸附动力学实验结果显示聚合物对沙拉沙星的吸附在7h达到平衡,选择性试验表明印迹聚合物对沙拉沙星具有较好的吸附特性。     

Removal of estrogenic pollutants from contaminated water using molecularly imprinted polymers

A synthetic molecularly imprinted polymer (MIP) sorbent for estrogenic compounds was prepared using a noncovalent imprinting technique. MIP microspheres sized from 1 to 2 microm were synthesized in acetonitrile by using alpha-estradiol as the template, acrylamide as the functional monomer, and trimethylpropanol trimethacrylate as the cross-linker. When compared with the nonimprinted polymer (NIP), the MIP showed outstanding affinity toward alpha-estradiol in aqueous solution with a binding site capacity (B(max)) of 380 nmol mg(-1) MIP, imprinting effect of 35, and a dissociation constant (Kd) of 38 microM. The MIP exhibited significant binding affinity toward other related estrogenic compounds such as beta-estradiol, diethylstilbestrol, estriol, and estrone, suggesting that this material may be appropriate for treating a complex mixture of estrogenic pollutants. The feasibility of removing estrogenic compounds from environmental water by the MIP was demonstrated using lake water spiked with alpha-estradiol. In addition, the MIP reusability without any deterioration in performance was demonstrated for at least five repeated cycles.     

Convenient solid phase extraction of cephalosporins in milk using a molecularly imprinted polymer

In this paper, a molecularly imprinted polymer (MIP) for cephalosporin molecules (cephalexin (CFL) and cephapirin (CFP)), was prepared by non covalent molecular imprinting approach and applied to solid phase extraction (SPE). For MIP synthesis, a tributylammonium cefadroxil salt (TBA-CFD) was used as template with methacrylic acid and ethylene glycol dimethacrylate as monomer and cross-linker, respectively, in acetone-methanol 92/8 (v/v) mixture. The selectivity of MIP versus non imprinted polymer (NIP) was confirmed for CFL, CFD and CFP in standard solutions as well as in milk samples. The efficiency of the synthesized MIP was evaluated by means of the application of the proposed MIP-SPE procedure to spiked milk samples previous to the HPLC method for the detection of cephalosporins. The MIP-SPE recoveries were higher than 60% for the three target analytes in spiked milk.     

Selective trace analysis of sulfonylurea herbicides in water and soil samples based on solid-phase extraction using a molecularly imprinted polymer

A molecularly imprinted polymer (MIP) was synthesized using the herbicide metsulfuron-methyl (MSM) as a template, 2-(trifluoromethyl)acrylic acid as a functional monomer, divinylbenzene as a cross-linker, and dichloromethane as a porogen. This polymer was used as a solid-phase extraction material for the quantitative enrichment of five sulfonylureas (nicosulfuron, thifensulfuron-methyl, metsulfuron-methyl, sulfometuron-methyl, and chlorsulfuron) in natural water and soil samples and off-line coupled to a reversed-phase HPLC/diode array detection (HPLC/DAD). Washing solvent was optimized in terms of kind and volume for removing the matrix constituents nonspecifically adsorbed on the MIP. It has been shown that the nonspecific binding ability of the sulfonylureas to the polymer largely increased along with increasing the concentration of Ca2+ ions in the water sample, whereas complexation of divalent ions with EDTA eliminated this interference completely. The stability of MIP was tested by consecutive percolation of water sample, and it was shown that the performance of the MIP did not vary even after 200 enrichment and desorption cycles. Recoveries of the five sulfonylureas extracted from 1 L of tap water and surface water samples such as river water and rainwater at a 50 ng/L spike level were not lower than 96%. The recoveries of sulfonylureas extracted from 10-g soil sample at the 50 microg/kg level were in the range of 71-139%. Depending on the particular compound, the limit of detection varied from 2 to 14 ng/L in water and from 5 to 12 microg/kg in soil samples. The MIP was also compared with a commercially available C-18 column and an immunoaffinity support with encapsulated polyclonal anti-MSM antibodies in sol-gel glass.     

An Electrochemical Nanosensor Based on Molecularly Imprinted Polymer (MIP) for Detection of Gallic Acid in Fruit Juices

The molecularly imprinted polymer (MIP)-based electrochemical sensor has been attending recently, due to their exceptional advantages and specificity. Here, we successfully designed and fabricated a novel electrochemical nanosensor for determination of gallic acid (GA) based on its specific MIP. The MIP was synthesized using precipitation polymerization technique, via polymerization of methacrylic acid as a functional monomer. The MIP was applied in the multiwalled carbon nanotube-modified carbon paste electrode (MWCNT–CPE), and similarly, MIP and MWCNT-modified CPE (MIP–MWCNT–CPE) was prepared, which acted as the selective recognition element and pre-concentrator agent for GA. The effect of different factors such as quantity of MIP and MWCNT, GA solution pH, and GA accumulation time on an oxidation current of accumulated GA at the electrode were investigated and optimized by central composite design (CCD) as a an experimental design and response surface methodology. The results showed that fabricated nanosensors (MIP–MWCNT–CPE) have higher sensitivity compared with bare CPE, MWCNT–CPE, and MIP–CPE. This sensor showed a linear response range of 0.12–380.0 μM and detection limit of 47.0 nM. Finally, the nanosensor was applied to determine GA in apple, pineapple, orange juices, and a commercial green tea drink as real samples with satisfactory results.     

Application of Molecularly Imprinted Polymer Appended onto CdSe/ZnS Quantum Dots for Optosensing of Tocopherol in Rice

Acting as a fluorescence sensing material, the molecularly imprinted polymer (MIP) appended onto quantum dots (QDs) was constructed through anchoring the MIP layer on CdSe/ZnS QDs by simple embedding for highly selective and sensitive optosensing of tocopherol (TP) in rice. The resulting composite of QDs with MIP showed higher template selectivity versus that of non-imprinted polymer (NIP). Under optimal conditions, the relative fluorescence intensity of MIP appended onto QDs decreased linearly (r ²?>?0.99) with the increasing TP in the concentration in the range of 1.16?×?10^?7–1.74?×?10^?3 mol L^?1 with a detection limit of 5.80?×?10^?8 mol L^?1, and the precision for five replicate detections of 1.0?×?10^?4 mol L^?1 TP was 2.17 % (relative standard deviation). Recoveries of 90.40 to 100.20 % were achieved by direct detection when MIP appended onto QDs was used for the selective separation of TP in rice samples.     

Preparation of Molecularly Imprinted Polymer Monolith with an Analogue of Thiamphenicol and Application to Selective Solid-Phase Microextraction

A molecularly imprinted polymer (MIP) monolith has been prepared and characterized. Its application to the assay of thiamphenicol in milk with high-performance liquid chromatography?Cphotodiodes array detector was validated. The newly developed MIP monolith was produced using an analogue to thiamphenicol as the template molecule to avoid major traditional drawback associated with MIPs of residual template bleeding. The MIP monolith synthesized in a micropipette tip could be connected with syringes in different sizes simply to perform solid-phase microextraction process without any other treatment. This molecularly imprinted polymer monolith microextraction (MIPMME) method showed high selectivity and enrichment ability for thiamphenicol (TAP). Several parameters affecting MIPMME were investigated, including the flow rate, volume, pH and salt concentration of sample, the type and volume of washing solution, and the type and flow rate of eluent. The recovery of this method for TAP was investigated and high recoveries of 93.5?~?96.8% from milk were obtained with relative standard deviations less than 6.3%.     

沉淀聚合法制备葛根素印迹微球及其固相萃取葛根粉

以葛根素为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂沉淀聚合法制备葛根素印迹聚合物微球。用扫描电镜观察微球形貌,静态吸附法测试聚合物的吸附行为。探讨分子印迹聚合物（molecularly imprinted polymers,MIPs）对葛根粗提液中葛根素的吸附、解吸附及固相萃取效能。结果表明,优化的葛根素MIP3对纯模板的静态吸附量达37.9 mg/g;对粗提液中目标化合物的吸附率为（96.3±1.81）%,以水、甲醇-醋酸（9∶1,V/V）及50%甲醇溶液为洗脱剂的单次解吸率为27%～34%,用水从MIP3上解吸出的总溶液经脱除溶剂后,所获粗品葛根素含量最高,达（37.4±2.87）%。在优化条件下,通过MIP3固相萃取葛根粗提液,葛根素回收率达71.6%,产品纯度高于75%。     

Molecularly imprinted solid-phase extraction of fumonisin B analogues in bell pepper,rice and corn flakes

A molecularly imprinted polymer (MIP) for the recognition of fumonisin B analogues (FB) using 2-(diethylamino) ethyl methacrylate (DEAEM) as functional monomer and trimethylolpropane trimethacrylate (TRIM) as cross-linker was prepared by bulk polymerization in acetonitrile. Fumonisin B₁ (FB₁) was used as a template molecule. A molecularly imprinted solid-phase extraction (MISPE) procedure was developed for further application in the analysis of FB. The performance of the MIP throughout the clean-up of spiked bell pepper, rice and corn flake sample extracts was compared with the results obtained when using non-imprinted polymer, C₁₈, strong anion exchange and immunoaffinity sorbents. Extracts were analysed for FB with liquid chromatography-tandem mass spectrometry (LC-MS/MS) after clean-up. Depending on the food matrix and the concentration range of the fumonisins, recoveries after MISPE varied from 62 to 86%, from 62 to 83%, and from 67 to 81% for fumonisin B₁ (FB₁), fumonisin B₂ (FB₂) and fumonisin B₃ (FB₃), respectively. The selectivity of the synthesized MIP for mycotoxins belonging to the group of FB was confirmed by evaluating cross-reactivity from analogue structures and other mycotoxins. Analysis of 39 naturally contaminated samples (corn flakes) by liquid chromatography tandem mass spectrometry indicated that the synthesized MIP could be an excellent alternative for clean-up and pre-concentration of FB in food samples. Pearson correlations between immunoaffinity clean-up and MISPE were calculated and amounted to 0.923 for FB₁, 0.808 for FB₂, and 0.759 for FB₃. It was shown that the developed MIP could be reused more than 50 times. The synthesis of an FB₁ imprinted polymer and its application in food analysis is reported for the first time.     

Synthesis and characterisation of a selective adsorbent based on the molecularly imprinted polymer for the removal of cloxacillin antibiotic residue from milk

In recent decades, environmental pollution has been a subject of growing concern. This is partly due to the overuse of antibiotics, the consequent drug resistance and the discharge of drugs into the environment. The aim of this study was to synthesise molecularly imprinted polymer (MIP) particles via a noncovalent procedure for the removal of cloxacillin from milk. Accordingly, the effects of operational parameters such as pH, contact time and MIP dosage were studied. The performance of MIP particles in removing cloxacillin from livestock milk samples proved that these adsorbents can effectively help to reduce drug contamination from dairy sources.