对甲基苯甲酸连接的氯霉素全抗原合成与鉴定

以对氯甲基苯甲酸(CBA)或对氯甲基苯甲酸甲酯(MCB)分别与氯霉素(CAP)反应合成氯霉素-对甲基苯甲酸半抗原(CAP-MBAⅠ、CAP-MBAⅡ),再与牛血清白蛋白(BSA)偶联制备全抗原;通过紫外、荧光光谱扫描定性鉴定合成成功;bradford法结合TNBS法定量计算出全抗原表面半抗原密度(HD)。再将CAP-MBAⅡ与卵清蛋白(OVA)合成包被抗原(CAP-MBAⅡ-OVA),间接竞争ELISA计算其抑制率。研究结果表明,半抗原全抗原偶联效率优于CAP-MBAⅠ,MCB与CAP反应合成的半抗原CAP-MBAⅡ更适合蛋白偶联。采用CAP-MBAⅡ-OVA作为包被抗原可以提高ELISA检测的抑制率从而增加其灵敏度。     

氯唑西林人工抗原的合成及其抗体的制备

为建立氯唑西林(cloxacillin,CLOX)残留的酶联免疫(enzyme-linked immuno sorbent assay,ELISA)检测方法,试验采用碳化二亚胺法,将氯唑西林偶联于载体蛋白牛清蛋白(Bovine albumin,BSA)和卵清蛋白(ovalbumin,OVA),制得免疫抗原(CLOX-BSA)和包被抗原(CLOX-OVA),并通过红外光谱扫描(infrared spectroscopy,IR)鉴定表明CLOX人工抗原合成成功。用免疫抗原免疫5只小鼠,制备CLOX多克隆抗体,通过间接ELISA法测定其对CLOX的效价及特异性。结果表明:用CLOX-BSA免疫制备的抗体效价达1∶64000以上,特异性较强,对CLOX的半抑制质量浓度IC50值为(5.64±0.03)ng/mL,IC15值为(22.43±0.02)ng/mL。说明试验得到了灵敏度高、特异性强及具有开发性的抗体,可为食品安全检验试剂盒的开发提供基础。     

苯甲酸人工抗原的合成与免疫效价的测定

通过苯甲酸的衍生物邻苯二甲酸酐(PA)的氨解法将苯甲酸(BA)偶联到载体蛋白上合成苯甲酸的人工抗原:免疫原苯甲酸-鸡卵清蛋白(BA-OVA)和包被原苯甲酸-牛血清白蛋白(BA-BSA).通过紫外光谱扫描、红外光谱扫描及SDS聚丙烯酰胺凝胶电泳的方法检测鉴定人工抗原,并用免疫原(BA-OVA)免疫BALB/c小鼠,检测抗体的生成.结果表明,苯甲酸人工抗原的合成成功.根据邻苯二甲酸酐、人工抗原和载体蛋白的紫外吸收值,计算出免疫原中苯甲酸(BA)与载体鸡卵清蛋白(OVA)的偶联比约为174:1.免疫小鼠血清中的抗体通过ELISA法检测为阳性(血清效价达到了1:3.2×10<'5>),表明合成的抗原已诱导出针对苯甲酸的特异性抗体生成,为进一步的苯甲酸单克隆抗体制各和免疫检测提供可靠的免疫原.     

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。     

莱克多巴胺和土霉素人工抗原的合成及鉴定

研究莱克多巴胺和土霉素免疫抗原的制备。实验中用碳二亚胺法将莱克多巴胺(ractopamine,RAC)与载体蛋白牛血清白蛋白(bovine serum albumin,BSA)偶联,制备完全抗原;采用混合酸酐法将土霉素(oxytetracycline,OTC)与载体蛋白BSA偶联,制备完全抗原,并对合成产物进行表征。紫外扫描对合成产物RAC-BSA、OTC-BSA进行鉴定结果显示偶联成功,经重氮化后利用混合酸酐法制备完全抗原的偶联比为5:1;经衍生后利用碳二亚胺法制备RAC完全抗原偶联比为7:1。利用制备的免疫原免疫兔子可以获得相应的抗体。     

强力霉素人工抗原的合成与抗体制备

采用改进的碳二亚胺两步法将强力霉素半抗原与载体蛋白BSA连接制备强力霉素-牛血清白蛋白(BSA-DC)人工免疫抗原,并用同样方法将强力霉素与载体蛋白OVA连接制备人强力霉素-卵清白蛋白(OVA-DC)人工包被抗原。经紫外扫描分析和动物免疫试验证实:强力霉素人工抗原合成成功,强力霉素与BSA的结合比为3∶1,经动物免疫试验所得抗血清效价为2.048×106,完全能够满足强力霉素残留的ELISA检测要求。     

环丙沙星衍生物的制备及其抗体特异性研究

本文研究了环丙沙星(CPLX)羧基衍生物及其抗体的制备,并对该衍生物抗体的特异性进行了测定。将环丙沙星与3-溴丙酸反应,生成环丙沙星的羧基衍生物(CPLX-COOH),通过制备液相进行纯化,用红外光谱(IR)、电喷雾电离质谱(ESI-MS)与核磁共振法(NMR)进行鉴定;将环丙沙星衍生物分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)进行偶联,分别制备免疫抗原(CPLX-COOH-BSA)和包被抗原(CPLX-COOH-OVA),并用紫外光谱法进行鉴定。用免疫抗原免疫BALB/c小鼠,制备环丙沙星衍生物多克隆抗体。通过ELISA方阵滴定法,确定包被抗原的最佳包被浓度和抗体最佳稀释度,建立了CPLX-COOH间接竞争ELISA检测方法,其半抑制浓度IC50为228.56 ng/mL,最低检出限(LOD)为25.527 ng/mL,该抗体具有广谱特异性,可与多种氟喹诺酮类药物发生交叉反应,可进行氟喹诺酮类药物残留的多元检测。     

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。     

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。     

沙丁胺醇多克隆抗体的制备与鉴定

为了对沙丁胺醇进行酶联免疫吸附法(ELISA)测定,通过四种方法制备沙丁胺醇衍生物,分别将其与牛血清蛋白(BSA)、卵清蛋白(OVA)偶联,制备人工完全抗原,采用紫外分光光度法测定蛋白质浓度并计算偶联比,用所制备的四种免疫原免疫新西兰白兔获得抗沙丁胺醇(SAL)抗体,每一种抗体都用四种包被抗原进行配对筛选,据此得到最佳的抗体-包被抗原的组合,对筛选出的抗体用正辛酸-硫酸铵法进行纯化,采用间接ELISA法测定多克隆抗体(pAb)的效价并进行特异性鉴定。结果表明:成功偶联了完全抗原,四种免疫原的偶联比分别为9:1、6:1、6:1、12:1,得到最佳的抗体-包被抗原的组合,筛选出的抗体效价达到1:64000,此抗体对克伦特罗和特布他林的交叉反应率分别为144%和169%,对其他类似物几乎没有交叉反应。本研究为沙丁胺醇、克伦特罗和特布他林多残留酶联免疫检测法的建立奠定了基础。     

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.     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.