盐酸西布曲明人工抗原的合成与鉴定

目的：建立盐酸西布曲明的免疫分析方法。方法：4-氯苯乙腈和1, 3-二溴丙烷为原料合成与盐酸西布曲明具有相同母核结构的小分子双去甲基西布曲明(M2),以双去甲基西布曲明为半抗原,并分别通过活泼酯法、戊二醛法和混合酸酐法将半抗原与牛血清白蛋白(BSA)和卵清蛋白(OVA)偶联制备免疫原(M2-BSA)和包被抗原(M2-OVA)。结果：紫外光谱扫描证明半抗原M2与载体蛋白偶联比为24.6:1(M2-BSA)和16.2:1(M2-OVA),抗血清ELISA效价均达到1:8000以上,IC50=0.42μg/mL。结论：半抗原M2与载体蛋白均已成功偶联,其中活泼酯法对半抗原活性基团的影响最小,合成人工抗原的特异性最强。     

对氯甲基苯甲酸链接的莱克多巴胺人工抗原的合成与鉴定

采用对氯甲基苯甲酸(CBA)为链接臂,用混合酸酐法将莱克多巴胺(RAC)与牛血清白蛋白(BSA)偶联制备人工抗原(RAC-CBA-BSA),通过紫外、红外、电泳鉴定抗原合成成功;再以卵清蛋白(OVA)为载体蛋白合成包被抗原(RAC-CBA-OVA),测定其与抗体的亲和力和抑制率。间接竞争ELISA结果以对CBA为链接臂合成的包被抗原对应的抗体滴度为7047.3、IC50为17.05ng/mL,结果表明,CBA可以用于RAC人工抗原的合成,使用RAC-CBA-OVA作为包被抗原可以提高ELISA检测灵敏度。     

氯霉素全抗原的合成与鉴定

目的：为获得较高偶联率氯霉素全抗原,探索和优化碳二亚胺法(EDC)合成氯霉素(CAP)与牛血清白蛋白(BSA)全抗原合成条件。方法：采用单因素设计,优化影响合成的主要因素：蛋白浓度、CAP 与BSA 的摩尔比例、反应体系pH 值,通过紫外法和三硝基苯磺酸(TNBS)法测定合成后的偶联率。 结果：EDC 法合成氯霉素抗原较优条件为BSA 浓度15mg/ml、CAP:BSA=70:1、pH7.4,可得到偶联率为15 左右的氯霉素全抗原。结论：EDC法可用于制备较高偶联率的氯霉素全抗原,以用来进行抗体制备。     

罗丹明123人工抗原的合成及抗体的酶联免疫检测

为建立罗丹明B(rhodamine B)的免疫分析方法,采用戊二醛法,将半抗原罗丹明123与载体牛血清白蛋白(BSA)及卵清蛋白(OVA)偶联制备免疫抗原R123-B S A和包被抗原R123-OVA。经动物免疫实验证实人工抗原合成,并制备抗罗丹明123的多克隆抗体,此抗体同时能够检测食品中的罗丹明B,且最低检测限为0.001ng/mL。     

泰拉霉素完全抗原的合成和鉴定

利用丁二酸酐法对泰拉霉素的羟基衍生化,引入游离羧基,合成泰拉霉素半抗原。采用活泼酯法将泰拉霉素半抗原分别与牛血清白蛋白(BSA)和鸡卵清白蛋白(OVA)偶联,合成人工完全抗原泰拉霉素-BSA和泰拉霉素-OVA。利用LC-MS鉴定衍生化后半抗原的合成,利用荧光光谱、考马斯亮法鉴定完全抗原的合成。用泰拉霉素-BSA免疫小鼠,采用间接ELISA法测定小鼠抗血清效价。泰拉霉素半抗原和BSA的偶联比为17∶1。三免后小鼠抗血清效价可达1∶8 000。     

氯霉素免疫抗原及包被抗原的制备

采用混合酸酐法合成30:1～10:1 三个不同起始物质的量比的氯霉素免疫抗原(HAP-KLH),采用活泼酯法(EDC-NHS)合成40:1～1:1 七个不同起始物质的量比的包被抗原(HAP-OVA),紫外测定HAP-KLH 偶联比25:1～8:1,HAP-OVA 偶联比23:1～1:3。间接竞争ELISA 实验优化包被抗原,在23:1～3:1 偶联比范围内,氯霉素(CAP) IC50值为36～15ng/mL,随着偶联比的减小而降低,当偶联比低于3:1 则略为上升。确定了包被抗原HAP-OVA 最佳偶联比为3:1。本研究表明包被抗原的偶联比对ELISA 测定IC50 值有重要影响,应合成不同偶联比的包被抗原,选出最佳偶联比。     

酸性橙Ⅱ半抗原及人工抗原的合成与鉴定

目的建立酸性橙Ⅱ半抗原及人工抗原的合成及鉴定方法。方法将重氮化后的2-氨基-5-磺基苯甲酸与2-萘酚经偶氮反应合成带羧基基团酸性橙Ⅱ,通过碳二亚胺法将其与载体蛋白(BSA)偶联制备酸性橙Ⅱ人工抗原。采用核磁共振碳谱和氢谱对合成的酸性橙Ⅱ半抗原进行结构分析,并用紫外光谱扫描法和蛋白质电泳法鉴定酸性橙Ⅱ人工抗原并计算偶联比。结果通过偶氮反应及碳二亚胺法最终得到纯化后的酸性橙Ⅱ半抗原约47 mg,核磁结果显示成功合成酸性橙Ⅱ半抗原。经SDS-PAGE、N-PAGE和紫外光谱扫描结果均显示酸性橙Ⅱ人工抗原蛋白分子质量大于BSA,所带负电荷大于BSA,且合成后的酸性橙Ⅱ人工抗原具有吸收峰叠加效应,均表明酸性橙Ⅱ人工抗原合成成功,偶联比为20.9:1。结论此方法能够成功合成酸性橙Ⅱ半抗原和人工抗原,为进一步制备特异性酸性橙Ⅱ抗体和建立酸性橙Ⅱ的免疫检测方法奠定基础。     

孔雀石绿多克隆抗体的制备与筛选

设计并成功合成了三种孔雀石绿半抗原,所有半抗原均采用活化酯法分别与血匙兰蛋白(KLH)偶联制备成免疫抗原,与卵清蛋白(OVA)偶联制备成包被抗原。利用所制备的三种免疫原免疫新西兰大耳白兔都获得了高效价的抗孔雀石绿抗体,并将每一种抗体都与三种包被抗原进行组合配对,通过间接竞争酶联免疫吸附检测(ELISA)方法筛选出最佳的抗体-包被抗原组合,筛选出的抗体采用Sepharose FF-Protein A亲和层析柱纯化,采用间接ELISA法测定效价及鉴定特异性。经测定筛选出的抗体效价达到1:12000,IC50值为0.65 ng/mL,交叉反应表明该抗体有较好的特异性,与结构类似物结晶紫的交叉反应率为18.73%,与隐性孔雀石绿及隐性结晶紫的交叉反应率低于10%。本研究为建立快速检测食品中孔雀石绿残留的免疫分析方法奠定了基础。     

对硫磷快速ELISA检测方法的建立

由于对硫磷的残留问题及其危害,迫切需要建立一种快速有效的农药检测方法。将对硫磷苯环上的硝基还原为氨基,得到了具有氨基活性的半抗原化合物———氨基对硫磷,然后采用重氮法将氨基-对硫磷与牛血清白蛋白(BSA)或卵清白蛋白(OVA)相偶联,分别合成了免疫原和包被抗原:氨基对硫磷-BSA、氨基对硫磷-OVA。对合成的抗原进行紫外可见扫描,确证偶联成功。用合成的免疫抗原免疫实验用大白兔,制备对硫磷的多克隆抗血清,效价达到1∶1×106以上。对硫磷抗体除了与甲基对硫磷具有极其微弱的交叉反应以外,与甲胺磷和毒死蜱交叉反应低于0.1%,最低检测限2.0ngg,回收率为93.3%。该方法简便、快速、灵敏,适用性强。     

两种方法制备氟苯尼考人工抗原及其鉴定

目的：通过两种不同方法制备氟苯尼考人工抗原并将制备的人工免疫原用于动物免疫。方法：分别采用琥珀酸酐法和强碱水解法制备两种人工半抗原(HP1 和HP2)。将两种半抗原与牛血清白蛋白(BSA)和卵清白蛋白(OVA)通过活泼酯法和戊二醛法进行偶联,制备人工免疫原和人工包被原,分别命名为HP1-BSA、HP1-OVA、HP2-BSA 和HP2-OVA。分别将两种方法合成的人工免疫原用于动物免疫,用两种人工包被原对获得的两种抗血清进行评价。结果：经质谱、紫外光谱表征,氟苯尼考两种半抗原均合成成功,并且与载体蛋白的偶联比分别为12.4:1(HP1-BSA)、8.5:1(HP1-OVA)、21.8:1(HP2-BSA)、15.4:1(HP2-OVA)。动物实验结果表明,获得的针对HP1-BSA的抗血清与HP2-OVA 包被原结合最为灵敏。结论：活泼酯法和戊二醛法均成功制备了氟苯尼考人工抗原。     

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