玉米赤霉烯酮一步ELISA法的建立及应用

为了建立一种快速、准确的检测饲料及其原料中玉米赤霉烯酮的酶联免疫一步法。在制备玉米赤酶烯酮半抗原、免疫原及单克隆抗体的基础上,运用方阵法确定包被抗原、抗体的浓度,筛选稳定的ELISA检测体系,并在此基础上考察了抗体的特异性。建立了检测饲料及其原料中玉米赤霉烯酮的方法,猪饲料、牛饲料、玉米渣和麦麸的检测限分别为96.2、92.7、80.5和86.7μg/kg。在饲料及原料中定量添加玉米赤霉烯酮,酶联免疫的回收率为79.4%~104.9%,开发的酶联免疫试剂盒与德国拜发试剂盒对实际样本进行检测,两种试剂盒对样本阴阳性判定一致。本研究为饲料及其原料中玉米赤酶烯酮的监管提供了技术支撑。      

免疫磁珠高通量自动净化-超高效液相色谱法快速测定饲料中玉米赤霉烯酮

采用免疫磁珠净化饲料原料及其产品中的玉米赤霉烯酮,实现玉米赤霉烯酮的自动富集、清洗和洗脱,结合超高效液相色谱对玉米赤霉烯酮进行分析测试。本文对饲料样品稀释液进行了优化。根据3倍信噪比的峰响应值,本方法玉米赤霉烯酮的检出限为4.5 μg/kg,定量限为15.0 μg/kg,在10~500 ng/mL范围内线性关系良好,相关系数（R2）为0.99993。玉米赤霉烯酮在鸡饲料和猪饲料样品中的加标回收率为92.6%~112.9%,相对标准偏差为1.0%~8.8%。对同一饲料基质进行连续4天同一浓度的加标实验,回收率为97.0%~98.9%,日间精密度在5.7%~5.9%。使用本方法与免疫亲和柱法进行比较,检测了19种饲料样品,t检验显示本方法与免疫亲和柱法无显著性差异。免疫磁珠自动净化法可同时净化24个样品,无需人员手动操作,减少实验误差,提高检测效率,满足饲料中玉米赤霉烯酮的日常检测要求。     

液相色谱法测定酱油中的玉米赤霉烯酮含量

玉米赤霉烯酮,它首先从感染赤霉病的玉米中分离得到。本文主要通过对国家标准检测方法 GB 5009.209-2016《食品安全国家标准食品中玉米赤霉烯酮的测定》的优化,采用甲醇水提取、免疫亲和层析净化、吹干、定容得待测试液,使用高效液相色谱仪荧光检测器进行检测。在最佳条件下,玉米赤霉烯酮在0.0~500.0ug/L范围内线性良好(r~2=0.999536),对酱油中的玉米赤霉烯酮含量进行分析检验,实验结果表明样品中加入三倍方法测定低限135μg/kg标液20平行试验RSD值为4.9%,加标回收率在86.0%~105.1%,方法检出限为51μg/kg。试验215μg/kg和500μg/kg两个水平的加标回收实验,重现性好,定量准确,结果令人满意。     

酶联免疫吸附法快速检测饲料中赭曲霉毒素A

目的建立一种酶联免疫吸附法(enzyme linked immunosorbent assay,ELISA)快速检测饲料中赭曲霉毒素A快速的方法。方法样品采用60%的甲醇溶液提取,提取液经过离心、快速滤纸过滤后,用稀释缓冲溶液按10倍的比例对提取液进行稀释即为试样液,采用酶联免疫吸附方法进行检测。结果在加标浓度为25、50和100μg/kg的加标水平下,赭曲霉毒素A在饲料中的加标回收率为88.4%~134.6%,变异系数为3.5%~6.9%。抽取10份样品进行检测,赫曲霉毒素A含量在14.1~38.2μg/kg。符合国家的标准GB 13078-2017对饲料中赫曲霉毒素A含量的规定。结论本方法灵敏度高、快速简便,适用于饲料中赭曲霉毒素A的快速批量检测。     

直接竞争酶联免疫法检测大麦中玉米赤霉烯酮

建立一种大麦中玉米赤霉烯酮的快速检测方法.采用酶联免疫吸附法(ELISA)对玉米赤霉烯酮进行测定.该方法的最低检出限(IC15)约为0.01 μg/kg,灵敏度(IC5)约为0.08μg/kg,大麦样品加标回收率在73.3%～96.7%之间,最低检出限为4μg/kg.此方法特异性强,灵敏度高,样品处理过程较为简单,适用于大量样品的快速检测.     

鸡饲料及原料中玉米赤霉烯酮污染的检测及分布研究

对污染鸡饲料及原料的有毒物质玉米赤霉烯酮的检测方法和分布进行了研究。建立了饲料及不同种类原料中玉米赤霉烯酮的高效液相色谱-荧光检测方法,采用免疫亲和柱进行净化处理,优化了样品提取和净化条件,获得了较好的色谱条件,能满足检测分析的需要。同时采用该方法分析了118批饲料和83批原料中玉米赤霉烯酮的含量。结果显示,该方法检出限为0.005mg/kg,回收率为87.2%~91.0%,精密度为1.2%~2.1%,能快速、准确地分析鸡饲料及原料中玉米赤霉烯酮的含量。玉米赤霉烯酮在原料中的总的检出率为8.4%,在原料干酒糟、蛋白粉、高粱、玉米中有检出,超出允许限量的原料占总数的10%。鸡饲料中玉米赤霉烯酮总的检出率为30.51%,超标率为5.08%。原料和饲料中玉米赤霉烯酮的最高含量分别为976.24、2042.44μg/kg,分别达到标准允许限量的2倍和4倍。     

基于单克隆抗体的玉米赤霉烯酮检测方法研究

建立一种检测谷物样品中玉米赤霉烯酮的酶联免疫分析方法。将玉米赤霉烯酮修饰羧基制得半抗原,再与钥孔嘁血蓝蛋白偶联,免疫BALB/c小鼠,经过细胞融合与筛选,得到3株具有高亲和力和特异性的杂交瘤细胞,分别为2E8、2C7、6E11,重链类型均为IgG_1,轻链类型均为Kappa。细胞株2E8分泌的抗体特异性较好,制备腹水得到单克隆抗体用于后续实验。建立检测玉米赤霉烯酮的间接竞争酶联免疫吸附(Enzyme-Linked Immunosorbent Assay,ELISA)方法,方法的灵敏度(IC_(50))为(0.13±0.02)ng/mL,检测限(IC_(15))为(0.02±0.01)ng/m L,在玉米和燕麦中的检出限分别为2.4μg/kg,4.0μg/kg。加标回收率为82.80%~109.20%,变异系数为3.27%~15.38%。经高效液相色谱串联质谱仪验证(R~2=0.996 3)二者具有良好的相关性。     

高效液相色谱法对玉米中玉米赤霉烯酮的测定

研究了高效液相色谱法测定玉米中玉米赤霉烯酮的方法.样品借鉴了GB/T 19540-2004中提取玉米赤霉烯酮的方法,通过Oasis HLB净化柱对提取液净化,以agilent extent C18色谱柱为分离柱,乙腈-水(V水:V乙腈=55:45)为流动相进行荧光检测(λex=235 nm,λem=460 nm).玉米赤霉烯酮的质量浓度在12～2 400μ/kg范围内呈良好线性,相关系数为0.9994,对添加高、中、低3个浓度玉米赤霉烯酮的玉米样品进行加标回收试验,平均回收率分别为96.736%、93.839%、86.240%,变异系数在1%～10%之间,最低检测限为10μ/kg.此方法对玉米中玉米赤霉烯酮的检测是可行的,且可给谷物中玉米赤霉烯酮检测方法优化提供参考.     

超高效液相色谱-三重四级杆质谱串联法测定粮谷中的玉米赤霉烯酮类真菌毒素的研究

建立了粮谷中玉米赤霉烯酮、α-玉米赤霉烯醇、β-玉米赤霉烯醇检测的超高效液相色谱-三重四级杆质谱串联的分析方法。样品经0.1%甲酸水-乙腈溶液提取,经免疫亲和柱净化,以水溶液(含0.1%甲酸)和甲醇(含0.1%甲酸)为流动相进行梯度洗脱,质谱以负离子模式扫描和多反应监测模式进行检测,以外标法定量。结果表明,玉米赤霉烯酮、α-玉米赤霉烯醇、β-玉米赤霉烯醇在1~100μg/L浓度范围内呈现良好的线性关系,线性相关系数均大于0.994,检出限为0.5~1.0μg/kg,在5、20、80μg/kg 3个添加水平下,平均加标回收率为87.2%~100.6%,相对标准偏差为3.2%~6.4%。本方法结果准确可靠,灵敏度高,可适用于粮谷中玉米赤霉烯酮类真菌毒素的检测。     

超高效液相色谱-串联质谱法测定玉米油中玉米赤酶烯酮的残留量

目的建立玉米油中玉米赤酶烯酮检测的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。方法样品经乙腈超声提取,经免疫亲和柱进行净化,采用Waters ACQITY BEH(2.1 mm×100 mm,1.7μm)色谱柱分离,以0.1%氨水溶液和乙腈为流动相进行梯度洗脱;质谱以负离子模式扫描和多反应监测(MRM)模式进行检测,以内标法定量。结果玉米赤酶烯酮在2~100μg/L浓度范围内呈良好的线性关系,在5、20、80μg/kg 3个添加水平下,加标回收率为90.2%~105.1%,相对标准偏差为1.66%~3.50%。玉米赤霉烯酮的检出限为1.0μg/kg,定量限为3.0μg/kg。结论本方法灵敏、结果准确可靠,可适用于玉米油中玉米赤酶烯酮的检测。     

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.     

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