ELISA法测定热加工食品中的丙烯酰胺

该研究建立了热加工食品中丙烯酰胺的间接竞争ELISA检测方法.首先用戊二醛法合成丙烯酰胺-BSA免疫抗原,注入兔体内以产生抗丙烯酰胺多克隆抗体.结果显示,在包被抗原为1.5μg/mL,抗体稀释度为1∶16000倍的优化条件下,间接ELISA法检测范围为50μg/L～1280μg/L,IC50为检测限为350μg/L,最低检测限为50μg/L.加标回收率为92.6%～95.5%.该检测方法准确快速,特异性强,适用于热加工食品中丙烯酰胺的快速检测.     

恩诺沙星时间分辨荧光免疫分析方法的建立

目的：采用时间分辨荧光免疫分析(time-resolved fluoroimmunoassay,TRFIA)技术建立高灵敏的恩诺沙星(enrofloxacin,ENR)快速检测方法。方法：以包被抗原(ENR-OVA)包被微孔板,与游离的恩诺沙星共同竞争抗恩诺沙星抗体,以铕(Eu3+)标记的羊抗兔抗体进行示踪。结果：方法的批内变异系数小于10%、批间变异系数小于15%,平均回收率为91.62%,灵敏度为5ng/L,可测范围为0.01～100μg/L,ED20、ED50和ED80分别为0.088、3.40μg/L和32.81μg/L。结论：ENR-TRFIA方法稳定性好、可测范围宽,具有很好的应用前景。     

直接竞争酶联免疫法测定呋喃妥因代谢物

目的建立动物组织中呋喃妥因代谢物1-氨基乙内酰脲的直接竞争酶联免疫(ELISA)检测法,为检测食品中呋喃妥因代谢物残留提供快速检测的方法。方法采用活化酯法制备辣根过氧化物酶标记抗原,并用棋盘法确定酶标抗原和抗体的稀释度,优化反应条件,建立检测呋喃妥因代谢物的直接竞争酶联免疫法,并对其进行方法学评价。结果该方法的线性方程为Y=-34.723X+158.01(r2=0.9922),线性检测范围为0.177~11.508ng/m L,IC50为1.291 ng/m L;猪肉、鸡肉、鱼肉的最低检测限分别为0.115、0.113、0.109μg/kg,加标回收率在82.6%~104.7%之间,批内变异系数在3.6%~9.3%之间,批间变异系数在4.3%~12.4%之间。结论本方法快速准确,适用于动物组织中呋喃妥因代谢物的检测。     

ELISA法与LC-MS/MS法测定动物组织中克仑特罗残留

目的:比较酶联免疫法(ELISA)和液相色谱-串联质谱法(LC-MS/MS)测定动物组织中克仑特罗残留量的准确度、精密度及检测限。方法:样品经过处理后,分别采用ELISA法和LC-MS/MS法进行测定;用ELISA法对组织样品进行初筛,测出阳性样品利用LC-MS/MS法进行确证。结果:应用ELISA法测定样品猪肉样品中克仑特罗的回收率为67.0%～99.6%,批内变异系数3.4%～8.7%,批间变异系数6.1%～9.6%,灵敏度为0.025μg/L,最低检测限0.025μg/kg;LC-MS/MS检测方法回收率88.62%～111.43%,批内变异系数4.4%～7.4%,最低检测限0.5μg/kg;用ELISA法对50份猪肉和50份猪肝样品进行检测,筛选出3个阳性样品,经LC-MS/MS确证为阳性,两种方法检测结果一致。结论:ELISA法灵敏度和准确度较高,样品处理方法简单,成本低,适合组织中克仑特罗残留大规模筛查;LC-MS/MS准确度高,适合于阳性样品精确定量。     

ELISA法检测牛奶中链霉素残留量

从抗原的制备、抗体的获得、酶结合物的合成等基础入手,建立了牛奶中链霉素残留量快速筛选检测方法,检测历时60min,方法的临界值为110μg/L。经试验证明该方法检测限可达20μg/L或以下,奶样用水稀释后可直接测定,批内变异系数小于20%,板间变异系数小于30%,200μg/L质量浓度处空白奶样添加回收率在60%-110%,符合快速筛选方法的要求。     

应用酶联免疫法检测鱼肉、蜂蜜中氯霉素的残留量

检测鱼、蜂蜜中氯霉素残留,以评价试剂盒性能为目的。用间接竞争酶联免疫分析法(ELISA法)对鱼肉、蜂蜜中的氯霉素残留量进行了测定。结果表明,标准曲线的R2为0.9943,线性方程y=-0.3668x+0.4353,IC50为0.71μg/L,线性范围为0.05～4.05 ng/mL。鱼肉和蜂蜜中的检测限分别为0.126μg/kg和0.081μg/kg。鱼肉和蜂蜜的添加回收率分别大于88.1%和85.5%,批内变异系数分别小于15.8%、13.6%,批间变异系数小于15.5%、12.3%。与氯霉素琥珀酸钠的交叉反应率为152.63%,与其他药物的交叉反应率均小于0.01%。该法测定氯霉素灵敏准确,重复性好,特异性高,适合用于检测鱼肉、蜂蜜中的氯霉素残留。     

牛初乳中sIgA双抗夹心ELISA检测方法的建立

为定量检测牛初乳中sIgA,建立双抗夹心ELISA方法。以牛初乳中的sIgA为抗原,免疫新西兰白兔,制得抗血清,经纯化后作为包被抗体;利用简易过碘酸钠法对兔抗牛sIgA标记辣根过氧化物酶(HRP),制得酶标抗体;通过方阵滴定法确定ELISA最佳工作条件;进行特异性、重复性、稳定性实验并且检测牛初乳粉样本中的sIgA含量。结果:成功建立了一种定量检测牛初乳中sIgA的双抗夹心ELISA方法。该方法线性范围:15.625～1 000μg/L;最低检测限(LOD)为15.625μg/L;精密度为:批内CV=4.8%;批间CV=6.5%。     

直接竞争化学发光酶免疫法检测猪肉中磺胺嘧啶

建立一种检测猪肉中磺胺嘧啶的简便、快速、高特异性的直接竞争化学发光酶免疫法。采用改良的过碘酸钠法制备酶标抗体,以辣根过氧化物酶催化鲁米诺-过氧化氢作为化学发光体系。经优化该方法检测条件为：利用柠檬酸缓冲液稀释抗原包被质量浓度为0.8μg/mL,酶标抗体2000倍稀释,竞争反应25min;所建立的方法分析灵敏度为2.96ng/mL,批内变异系数小于8.32%,批间变异系数小于13.4%,以猪肉为样品的分析回收率为75.6%～103.7%,与其他结构类似物未见明显交叉,所建立的标准曲线相关系数为0.9922、检测线性范围为4.14～244ng/mL、检测时间为25min,可在实际生产中应用。     

直接竞争酶联免疫吸附法检测虾过敏蛋白

目的:建立酶标抗原的直接竞争酶联免疫吸附法(dcELISA)检测食品中虾过敏蛋白,为食品过敏诊断试剂的开发和应用提供理论基础。方法:提取虾主要过敏蛋白,免疫小鼠制备抗虾过敏蛋白多克隆抗体,辣根过氧化物酶(HRP)标记抗原,建立酶标抗原的dcELISA检测虾过敏蛋白。结果:所建立的dcELISA法最低检测限为3.94ng/mL,标准曲线在0.12～128.86ng/mL范围内线性良好,批内和批间变异系数分别为6.16%和2.73%,回收率为82%～98%。结论:该方法具有良好的特异性、敏感性和稳定性,为进一步研制检测虾过敏蛋白的ELISA试剂盒提供有效的方法。     

纺织材料中邻苯二甲酸二丁酯检验试剂盒的研究北大核心

以甲醇为萃取剂,超声波辅助萃取纺织材料中的邻苯二甲酸二丁酯。用制备的邻苯二甲酸二丁酯人工全抗原免疫Balb/c小鼠,生成特异性抗体,建立了一种可检测样品中邻苯二甲酸二丁酯的固相抗原竞争ELISA方法。试剂盒的灵敏度为1.64μg/L,对邻苯二甲酸二丁酯的回收率为91.2%~94.7%,变异系数小于10%。可用于纺织材料中邻苯二甲酸二丁酯质量浓度的日常监管。     

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.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the