无需衍生化样品处理快速测定食品中黄曲霉毒素B_1

目的建立无需衍生化法.超高效液相色谱直接测定食品中的黄曲霉毒素B_1的快速检测方法。方法样品经甲醇.水(7:3,v:v)提取,免疫亲和柱净化,C_(18)色谱柱分离后,采用大体积流通池荧光检测器检测。结果黄曲霉毒素B_1在0.10~5.00 ng/mL范围内与峰面积呈良好线性关系,R~20.999,在饼干、粉丝、点心、沙琪玛、蛋糕、辣椒酱6种基质中,黄曲霉毒素B_1在0.50~2.00μg/kg范围内加标,平均回收率在71.7%~111.2%之间,相对标准偏差(RSDs)为3.8%~11.5%,检出限(LOD)为0.05 gg/kg。结论本方法灵敏、快速、无衍生、结果准确,能够满足食品中黄曲霉毒素B_1残留的检测需求。     

无需衍生化样品处理快速测定食品中 黄曲霉毒素B1

建立无衍生-超高效液相色谱法测定食品中的黄曲霉毒素B1的快速检测方法。样品经甲醇-水提取,免疫亲和柱净化,C18色谱柱分离、大体积流通池荧光检测器检测。黄曲霉毒素B1在0.10 ng/ml~5.00 ng/ml范围内与峰面积呈良好线性关系,R2>0.999,在6种基质,0.50 μg/kg~2.00 μg/kg范围内加标,平均回收率在71.7%~111.2%之间,相对标准偏差(RSD)为3.8%~11.5%,检出限(LOD)为0.05 μg/kg。本方法灵敏、快速、无衍生、结果准确,能够满足食品中黄曲霉毒素B1残留的检测需求。     

超高效液相色谱检测奶及奶制品中的M族黄曲霉毒素

目的建立一种免疫亲和柱净化-超高效液相色谱法同时测定奶及奶制品中M族黄曲霉毒素的方法。方法以乙腈为提取剂和蛋白沉淀剂,采用涡旋混合及超声提取,免疫亲和柱净化。结果经Welch Ultimate XB-C18色谱柱(100 mm×2.1 mm,1.8μm)分离,应用大体积流通池荧光检测,流动相为水和乙腈/甲醇(1:1)。线性范围在0.01~5.00 ng/mL之间,线性系数均大于0.999,黄曲霉毒素M1、M2的检出限为0.003μg/kg。免疫亲和柱对黄曲霉毒素M1、M2的回收率均在80%以上,液态奶中添加0.05、0.2、1.0μg/kg的回收率在85.6%~106.4%之间,奶粉中添加0.5、2.0、10.0μg/kg的回收率在81.5%~93.4%之间。结论该方法可以适用于奶粉、液态奶中M族黄曲霉毒素检测。     

高效液相色谱-光化学柱后衍生法测定紫苏籽中黄曲霉毒素B1

目的建立一种高效液相色谱-光化学柱后衍生法测定紫苏籽中黄曲霉毒素B_1的检测方法。方法样品经乙腈-水溶液(84:16,V:V)提取,用免疫亲和柱净化后,经光化学衍生器衍生,在高效液相色谱仪荧光检测器上检测。结果该方法对黄曲霉毒素B_1的最低检测限为0.05μg/kg,定量限为0.20μg/kg,相关系数为0.9990,加标回收率为86.0%～93.5%,相对标准偏差(relative standard deviation, RSD)为1.94%。结论该方法快速、准确、灵敏,适合测定紫苏籽中黄曲霉毒素B_1的含量。     

啤酒酿造原料中黄曲霉毒素B_1、玉米赤霉烯酮和赭曲霉毒素A同时检测分析方法研究

研究建立同时检测啤酒及酿造原料中黄曲霉毒素B1、玉米赤霉烯酮和赭曲霉毒素A的免疫亲和柱净化-柱后化学衍生-高效液相色谱方法。样品经过甲醇-水(80∶20,v/v)提取,通过免疫亲和柱进行富集和净化,采用Thermo BDS HYPERSIL C18色谱柱,以乙腈-2%乙酸(40∶60,v/v)为流动相,等度洗脱,柱后以0.5%碘溶液衍生、改变波长荧光检测。结果表明,黄曲霉毒素B1、玉米赤霉烯酮和赭曲霉毒素A检出限分别为0.05μg/kg(AFB1)、3.19μg/kg(ZEA)和0.22μg/kg(OTA),标准曲线的线性范围分别为0.2~10.0μg/L、10.0~1000.0μg/L和5.0~50.0μg/L;在大麦样品中加标回收率为90.0%~109.5%,相对标准偏差为2.18%~4.94%。被检37个样品的真菌毒素含量检测结果表明,正常贮存下的啤酒原料均未检测出真菌毒素,但在霉变大麦样品中可以检测出少量的真菌毒素。     

液液萃取-HPLC法测定食品中黄曲霉毒素B_1

建立一种液液萃取净化,结合柱后碘衍生-高效液相色谱检测食品中黄曲霉毒素B1的新方法。食品中黄曲霉毒素B1采用乙腈-水(85︰15, V/V)混合溶液提取,加入蛋白沉淀剂和正己烷除去蛋白质及脂溶性杂质,经三氯甲烷萃取净化、浓缩及定容后用柱后碘衍生-高效液相色谱荧光检测器进行检测。结果表明,在0.1～50.0 ng/mL浓度范围内,线性关系良好,拟合系数为0.999 97,在3倍信噪比下计算方法检出限为0.02μg/kg;分别对多种样品进行低(0.4μg/kg)、中(4.0μg/kg)、高(40μg/kg)加标回收率试验,回收率范围为75.9%～94.7%,相对标准偏差(RSD, n=6)为0.1%～5.4%。该方法分析速度快,准确度高,重复性好,适用于食品中黄曲霉毒素B1的检测。     

免疫亲和柱净化-在线柱后光化学衍生-高效液相色谱-荧光检测法快速测定食品中的黄曲霉毒素含量

目的 通过建立免疫亲和柱净化-在线柱后光化学衍生-高效液相色谱-荧光检测法探索快速测定食品中的黄曲霉毒素含量的方法。方法 样品经甲醇-水(V/V, 7︰3)提取, 免疫亲和柱净化、富集、淋洗后, 收集洗脱液, 洗脱液经Acclaim?120 C18 柱分离, 在254 nm紫外光下进行光化学衍生, 用荧光检测器进行测定。结果 黄曲霉毒素G2, G1, B2, B1检测限均小于2 μg/kg, 加标回收率为94.3%~108.8%。 结论 该方法能连续操作, 节省人力, 可用于食品中黄曲霉毒素含量的测定。     

免疫亲和柱净化-高效液相色谱柱后光化学衍生- 荧光检测器检测食品中黄曲霉毒素

目的建立一种免疫亲和固相萃取柱净化-高效液相色谱柱后光化学衍生-荧光检测器同时测定食品中黄曲霉毒素B_1、B_2、G_1和G_2的方法。方法以甲醇-水(70:30,V:V)为提取溶剂,采用高速均质提取,并经过黄曲霉毒素免疫亲和柱净化。结果经月旭公司Welch Ultimate~XB-C_(18)色谱柱(250 mm×4.6 mm,5μm)分离后使用光化学衍生器进行柱后衍生,并采用带荧光检测器的高效液相色谱仪检测,流动相为甲醇/水(45:55,V:V)。黄曲霉毒素B_1、B_2、G_1和G_2线性范围在0.3~50.0μg/L之间,线性相关系数均大于0.999,B_1、B_2、G_1和G_2检出限分别为0.15μg/kg、0.05μg/kg、0.15μg/kg、0.05μg/kg。在3个加标浓度下大米、花生和瓜子等试样的回收率在80.7%~92.6%之间;相对标准偏差(RSD)在2.04~3.87%之间。结论该方法的灵敏度、准确度和精密度均符合黄曲霉毒素的检测技术要求,且简便快速,适用于食品中黄曲霉毒素B_1,B_2,G_1和G_2的准确测定。     

IAC-HPLC法检测牛奶中黄曲霉毒素和玉米赤霉醇及类似物质量分数

建立了IAC-HPLC(免疫亲和柱净化-高效液相色谱)法检测牛奶中6种黄曲霉毒素和玉米赤霉醇及类似物的方法。样品经免疫亲和柱净化后,黄曲霉毒素用高效液相色谱——荧光检测器柱后衍生检测,玉米赤霉醇及其类似物用高效液相色谱——紫外检测器检测。结果表明,牛奶中黄曲霉毒素(M2,M1,G2,G1,B2,B1)的检测限分别为0.004,0.004,0.004,0.003,0.002,0.002μg/L,6种黄曲霉毒素的平均回收率在91.20%~113.8%之间,变异系数小于8.79%;玉米赤霉醇及其类似物的检测限均为0.05μg/L,平均回收率在54.22%~90.76%之间,变异系数小于9.44%。     

牛奶中6种黄曲霉毒素的3种液相色谱法比较

比较了牛奶中黄曲霉毒素测定的3种液相色谱分析方法。样品经直接稀释、免疫亲和柱净化,以乙腈-甲醇-水体积比(22︰22︰46)为流动相,分别经柱后光化学衍生化、未衍生化及碘衍生化-液相色谱-荧光法进行测定。柱后光化学衍生化,黄曲霉毒素M_2,M_1线性范围为0.02~20μg/L,G_2,B_2 0.005~20μg/L,G_1,B_1 0.01~20μg/L,相关系数≥0.999,定量限为0.000 5~0.002μg/kg,加标回收率79%~116%;柱后碘衍生化,M_2,M_1线性范围分别为0.02~20,0.05~20μg/L,其余4种均为0.01~20μg/L,相关系数≥0.999,定量限0.001~0.005μg/kg,回收率74~121%;未经衍生化直接进样,G_2,B_2线性范围0.005~20μg/L,其余4种为0.02~20μg/L,相关系数≥0.998,定量限0.000 5~0.003μg/kg,回收率82%~121%。结果表明,柱后光化学衍生测定6种黄曲霉毒素在线性范围、灵敏度和定量限等方面均具有优势。     

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