胶体金免疫层析法快速检测T-2毒素的研究

应用胶体金免疫层析技术,建立了一种快速检测谷物和饲料中T-2毒素的方法.采用柠檬酸三钠还原法制备胶体金颗粒,标记抗T-2毒素单克隆抗体并喷涂于玻璃纤维上,T-2毒素偶联抗原和羊抗鼠二抗分别喷涂于硝酸纤维素膜上,作为检测线和质控线,依次将样品垫、胶体金垫、硝酸纤维素膜和吸水垫组装成试纸条并装入检测卡中.测试结果表明,T-2毒素快速检测试纸条的检测限为0.Smg/L,检测时间为10min,假阳性率和假阴性率均为0.该法使用简单方便,非常适合现场快速检测谷物和饲料中的T-2毒素.     

胶体金免疫层析法快速检测黄曲霉毒素B1的研究

本文应用胶体金免疫层析技术,建立了一种快速检测食品中黄曲霉毒素B1的方法。采用柠檬酸三钠还原法制备胶体金颗粒,标记抗黄曲霉毒素B1单克隆抗体并喷于玻璃纤维上,黄曲霉毒素B1偶联抗原和二抗鼠抗驴分别结合于硝酸纤维膜上,依次将样本垫、胶金垫、硝酸纤维膜和吸水纸组装切割成胶体金试纸条并装入检测卡中。测试结果表明黄曲霉毒素B1快速检测试纸条的灵敏度为5ng/ml,检测时间为10min,批内和批间重复性为100%,假阳性率和假阴性率均为0。使用简单方便,非常适合现场快速检测黄曲霉毒素B1。     

胶体金免疫层析法快速检测赭曲霉毒素A研究

该研究应用胶体金免疫层析技术建立一种快速检测食品和饲料中赭曲霉毒素A方法。采用柠檬酸三钠还原法制备胶体金溶液,标记抗赭曲霉毒素A单克隆抗体,标记胶体金抗体喷涂于玻璃纤维上,赭曲霉毒素A偶联抗原OTA-OVA和二抗兔抗鼠IgG分别喷涂于硝酸纤维膜上作为检测限和质控线,依次将样品垫、胶体金垫、硝酸纤维膜和吸水纸组装成试纸条并装卡。测试结果表明,赭曲霉毒素A快速检测试纸条灵敏度为5 ng/mL,检测时间为10 min,批内和批间重复性为100%,假阳性率和假阴性率均为0。该法简单方便,非常适于现场快速检测赭曲霉毒素A。     

三甲氧苄氨嘧啶胶体金免疫层析检测试纸条的研制

应用胶体金免疫层析技术建立了一种快速检测食品中三甲氧苄氨嘧啶(TMP)的方法.采用柠檬酸三钠还原法制备胶体金颗粒,标记抗TMP单克隆抗体并冻干于聚苯乙烯微孔中,TMP-OVA和羊抗鼠二抗分别结合于硝酸纤维膜上,依次将样品垫、硝酸纤维膜和吸水纸组装,切割成胶体金试纸条.测试结果表明,TMP快速检测试纸条的灵敏度为50 μg/L,检测时间为5min,特异性高,批内和批间重复性良好,与ELISA试剂盒方法和LC-MS/MS方法符合率为100％.使用简单方便,适合现场快速检测TMP.     

T-2毒素快速定量检测试纸条的研究

为研制一种快速定量检测玉米中T-2毒素含量的胶体金试纸条,对T-2毒素单克隆抗体进行标记并对胶体金试纸条性能进行研究。用胶体金标记T-2毒素单克隆抗体,通过测定加入不同量碳酸钾后吸光度值的变化,确定标记的最佳pH值,通过与抗原进行正交试验确定最佳组合条件,应用胶体金定量读数仪通过检测线和对照线的对比,检测试纸条的性能。结果表明,单克隆抗体标记的最佳pH值为8.5,最佳标记浓度为20μg/mL,抗原的包被浓度为0.5mg/mL,羊抗鼠IgG的包被浓度为1.0mg/mL,试纸条检测T-2毒素标准品的检测限为5μg/kg。T-2毒素胶体金快速定量检测试纸条检测方法可得出具体数据,与常见真菌毒素无交叉反应,回收率在77%~117.6%之间,批内和批间重复性检测变异系数小于10%,玉米中T-2毒素的检测结果与高效液相法检测结果一致。T-2毒素胶体金快速定量检测试纸条可用于玉米中T-2毒素含量的快速定量检测。     

赭曲霉毒素A胶体金快速检测试剂条的研制

为建立一种快速检测饲料中赭曲霉毒素A的检测方法,应用胶体金免疫层析技术,研制了一种饲料中赭曲霉毒素A的免疫胶体金快速检测试剂条.将羊抗鼠IgG、特异性结合抗原和金标抗体三者经过反复调试优化,以适宜浓度和包被量分别包被到硝酸纤维素膜和胶体金结合垫上,包被后的硝酸纤维素膜、样品垫、胶体金结合垫、吸水垫及其他辅料组装成试剂条.试剂条的最低检测限为25μg/kg,与其他霉菌毒素的交叉反应率小于1％.该试剂条可用于饲料中赭曲霉毒素A的快速检测.     

玉米赤霉烯酮胶体金快速检测试剂板的研制

目的 应用胶体金免疫层析技术, 研制一种玉米等谷物中玉米赤霉烯酮残留免疫胶体金快速检测试剂板。方法 将制备的羊抗鼠IgG、人工结合抗原和金标抗体三者经过反复调试优化, 以适宜浓度和包被量分别包被到硝酸纤维素膜和胶体金结合垫上。包被后的硝酸纤维素膜和样品垫、胶体金结合垫、吸水垫及其他辅料组装成试纸条。结果 该试剂板的最低检测限为100 μg/kg, 整个检测过程仅15 min, 与其他霉菌毒素无交叉反应。结论 该试剂板可用于玉米赤霉烯酮残留快速检测。     

苯甲酸免疫胶体金快速检测试纸条的研制

应用胶体金免疫层析技术,制备苯甲酸胶体金免疫层析快速检测试纸条,采用柠檬酸三钠还原法制备颗粒直径为17nm的胶体金,将苯甲酸金标抗体喷涂在玻璃纤维垫上制成胶体金结合垫,将包被抗原和二抗羊抗兔分别结合于硝酸纤维膜作为检测线(T线)和质控线(C线),组装成胶体金免疫层析试纸条并进行灵敏度测试.结果显示,胶体金试纸条检测限为100μg/L,可在5～7min内完成测试,与苯酚、甲苯、苯乙酸、苯丙氨酸等药物均无交叉反应,检测结果与酶联免疫吸附法完全一致.该方法具有操作简便、快速、特异性强、灵敏度高等特点,适用于现场快速检测和筛选工作,具有广泛的商业开发应用前景.     

原料乳中玉米赤霉烯酮胶体金免疫试纸条检测方法的建立

采用柠檬酸三钠法合成胶体金,与抗玉米赤霉烯酮单抗(ZEA-m Ab)制成抗体-胶体金标记物,包被于胶体金结合垫上。玉米赤霉烯酮半抗原和蛋白的偶联物(ZEA-BSA)和羊抗鼠Ig G分别喷涂于硝酸纤维素膜作为检测线(T线)和质控线(C线),建立原料乳中玉米赤霉烯酮(ZEA)的胶体金免疫试纸条检测法。结果显示,试纸条的灵敏度为30n g/m L,与其他毒素无交叉反应,10 min内即可肉眼观察结果。检测添加有玉米赤霉烯酮的原料乳样品,该试纸条的检测限为50 ng/m L。方法可用于原料乳中玉米赤霉烯酮的快速检测。     

胶体金试纸条法快速筛查小麦和玉米中脱氧雪腐镰刀菌烯醇的研究

以抗脱氧雪腐镰刀菌烯醇(Deoxynivalenol,DON)单克隆抗体为基础,建立了胶体金免疫层析试纸条检测方法,用于小麦和玉米中DON的快速检测。采用柠檬酸三钠还原法制备胶体金,标记抗DON单抗并喷于玻璃纤维垫上,DON-BSA和驴抗鼠二抗均匀划于NC膜上检测线和质控线位置,依次将样本垫、结合垫、NC膜和吸水纸组装切割成试纸条并装入检测卡中。测试结果表明:该胶体金试纸条对纯标准品和人工污染样品的检测灵敏度分别为100μg/kg和500μg/kg,与除15-乙酰脱氧雪腐镰刀菌烯醇外的21种生物毒素均无交叉反应,重复性和稳定性均良好,对实际样品的检测结果与液相色谱串联三重四级杆质谱(LC-MS/MS)比对结果相符。该检测方法非常适合用于现场的快速筛查,具有良好的应用前景。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

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.     

European priorities for research to support legislation in the area of food contact materials and articles

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.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

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.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.