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1.
结合磁性分离技术和表面分子印迹技术,以改性Fe3O4为核、罗丹明6G分子印迹聚合物膜为壳,制备核-壳型磁性分子印迹聚合物微纳米材料。研究其对罗丹明6G的吸附性能,探讨了吸附动力学、吸附等温线及分子识别性,并将它应用于食品中分离富集罗丹明6G。结果表明:所制备的核-壳型磁性分子印迹聚合物具有高吸附容量(表观最大吸附量达24.69 mg/g)、快速的结合动力学(20 min达吸附平衡)及显著的吸附选择性(印迹因子达4.20)。以其作为新型固相萃取材料,结合高效液相色谱检测,对加标食品样品中的罗丹明6G进行分离、纯化、检测,加标回收率为92.3%~99.2%;相对标准偏差为0.85%~1.12%;检出限为0.003 8μg/m L。在外加磁场作用下分子印迹聚合物可快速与样品基质分离,提高了实验效率。本方法简单快速,可应用于食品中非法添加的罗丹明6G的分离检测。  相似文献   

2.
采用分子印迹技术,以间苯氧基苯甲醛为模板分子,纳米Si O2为载体,氨基硅烷(3-Aminopropyl triethoxy silane,APTES)为功能单体,四乙氧基硅烷(tetraethyl orthosilicate,TEOS)为交联剂,通过溶胶-凝胶法制备得到表面印迹聚合物(molecularly imprinting polymers,MIPs),并通过红外光谱和扫描电镜对其进行表征。以高锰酸钾为显色指示剂结合分子印迹聚合物,建立了检测间苯氧基苯甲醛的新方法,并优化了检测方法的条件。结果表明,印迹聚合物的饱和吸附量约是非印迹聚合物(non-imprinted polymers,NIPs)的2.5倍。在搅拌吸附时间为10min时,可达到最大吸附量;超声洗脱时间为10min时,即可洗脱完全,实验结果表明该印迹聚合物对间苯氧基苯甲醛具有较好的选择性,检测限可达到0.9μg/m L。该方法在江水中进行加标回收实验的回收率在82.7-92.8%。  相似文献   

3.
以植酸为模板分子,甲基丙烯酸(MAA)为功能单体,N,N'-乙烯基丙烯酰胺(EBA)为交联剂,过硫酸铵为引发剂,采用本体聚合法制备对植酸具有高特异选择性的植酸分子印迹聚合物(MIPs)。通过扫描电镜观察了分子印迹聚合物表面的结构,利用红外光谱进一步对其化学结构进行表征。通过动态吸附、静态吸附和选择性吸附考察了其吸附性能。研究表明植酸分子印迹聚合物对植酸的吸附高于对肌醇的吸附,植酸在印迹聚合物中的印迹因子为1.70,而与植酸结构相似物肌醇的印迹因子为1.46。解吸80 min,MIPs解吸达到稳定,解吸率达到89.59%。植酸分子印迹聚合物对植酸的吸附特异性强,对植酸的吸附量为21.38μmol·g~(-1),解吸效果好,进行吸附-解吸附循环5次后,植酸印迹聚合物的性能稳定,对植酸吸附容量为65.62μmol·g~(-1),是第一次吸附容量的90.00%,可重复使用。  相似文献   

4.
以交联化壳聚糖微球为表面载体,水和乙腈为混合溶剂,将模板分子(喹乙醇),功能单体(丙烯酰胺)及交联剂(N,N’-亚甲基双丙烯酰胺)采用表面分子印迹与溶胶-凝胶法合成喹乙醇分子印迹聚合物(MIP)。并对新型水相分子印迹聚合进行红外光谱、扫描电镜、吸附动力学实验、吸附平衡实验、选择性实验的表征。实验结果表明:以壳聚糖为载体的分子印迹聚合物对喹乙醇的吸附容量为10.14mg·g-1,对喹烯酮的印迹效率因子为2.29,乙酰甲喹的印迹效率因子为2.22。以壳聚糖为载体的分子印迹聚合物具有较高识别选择能力,对喹乙醇具有快速吸附效果。  相似文献   

5.
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.  相似文献   

6.
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。  相似文献   

7.
以表儿茶素为模板分子,丙烯酰胺为功能单体,偶氮二异丁腈作为引发剂,乙二醇二甲基丙烯酸酯为交联剂,通过原位聚合法制备分子印迹聚合物。首先考察不同模板分子、功能单体、交联剂比例条件下表儿茶素分子印迹聚合物的特异性吸附能力。结果表明表儿茶素与丙烯酰胺、乙二醇二甲基丙烯酸酯物质的量比为1∶6∶40时,分子印迹聚合物的吸附效果最佳,其模板分子回收率KMIPs为84.62%,特异性识别因子Q为4.55;然后利用扫描电子显微镜和红外光谱技术对制备的印迹聚合材料进行表征;最后在毛细管电泳最优条件下对加载过固相萃取柱的过柱液与洗脱液进行检测,建立分子印迹固相萃取-毛细管电泳联用检测表儿茶素的方法。实验结果表明,分子印迹聚合物成功聚合,形貌良好且具有专一吸附特性。该方法适用于六堡茶中表儿茶素的检测。  相似文献   

8.
以辣椒素为模板分子,采用本体聚合法合成以2-乙烯吡啶(2-VP)、丙烯酰胺(AM)为功能单体的辣椒素分子印迹聚合物(MIPs)。采用平衡结合实验评价其对辣椒素的特异性吸附能力;吸附动力学实验评价其对辣椒素的饱和吸附时间;选择性吸附实验评价其对辣椒素类似物的选择性吸附能力。结果表明,当辣椒素与2-乙烯吡啶、丙烯酰胺的物质的量比为1:2:2时,分子印迹聚合物对辣椒素的吸附效果最佳,其吸附容量为20.46mg/g,识别因子α=3.05;饱和吸附时间为6h;且对辣椒素有较好的选择吸附性。采用分子印迹聚合物对辣椒素进行固相萃取,考察极性不同的淋洗剂对辣椒素特异性吸附和非特异性吸附的洗脱效果,发现以极性较小的氯仿作为淋洗剂时能较大限度保留MIPs固相萃取柱中辣椒素的特异性吸附,并除去非特异性吸附。  相似文献   

9.
为解决桔霉素分子印迹聚合物在构建和应用过程中模板分子泄露和功能单体筛选工作量大的问题,以1-羟基-2-萘甲酸为假模板分子,基于液相色谱法构建桔霉素和1-羟基-2-萘甲酸的同时检测方法,该方法对分子印迹洗脱液中的两种目标物具有良好的回收率(≥95%),也能对功能红曲醇提液中桔霉素进行分离。运用量子化学方法,通过分子构型优化、原子电荷分布计算和结合能计算优选了构建分子印迹聚合物的功能单体2,6-二氨基吡啶。以响应面对其制备工艺进行优化,优化后的聚合物对桔霉素的吸附载量为(195.10±13.21)ng/g,相比优化前提高了0.79倍。以甲基丙烯酸为功能单体构建的桔霉素分子印迹聚合物为对照,对比了优化后的聚合物和对照聚合物的吸附性能,前者对桔霉素的吸附载量为后者的3倍,证实计算机模拟技术在桔霉素分子印迹聚合物构建中的实用性,旨在为分子印迹聚合物的构建和桔霉素富集与检测提供参考。  相似文献   

10.
以西维因为模板分子,甲基丙烯酸为功能单体,双官能团试剂甲基丙烯酰氧丙基三甲氧基硅烷为交联剂,添加适量的离子液体1-丁基3-甲基咪唑-6-氟磷酸盐,采用有机-无机杂化技术制备西维因分子印迹聚合物。通过优化合成条件,得到3者最佳反应物质的量比为1∶4∶7,离子液体的添加剂量为25μL/m L。该印迹聚合物对西维因的吸附容量达到3.21 mg/g,明显高于非印迹的吸附用量0.72 mg/g。西维因在印迹聚合物中的分配系数Kd为211.35,明显高于两种类似物——速灭威和异丙威。采用有机无机杂化方法得到的分子印迹聚合物对西维因具有良好的选择吸附能力。  相似文献   

11.
Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.  相似文献   

12.
An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.  相似文献   

13.
The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.  相似文献   

14.
The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.  相似文献   

15.
A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.  相似文献   

16.
BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H2O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.  相似文献   

17.
A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.  相似文献   

18.
19.
The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.  相似文献   

20.
Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH3CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH2PO4-20.6 mM Na2B4O7 buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.  相似文献   

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