同位素内标-高效液相色谱质谱法测定婴幼儿配方乳粉中维生素B6和生物素

目的建立同位素内标和高效液相色谱串联质谱法(highperformanceliquidchromatographytandem mass spectrometry, HPLC-MS/MS)同时测定婴幼儿配方乳粉中维生素B_6含量(吡哆醛、吡哆醇和吡哆胺)和B_7(生物素)的分析方法。方法样品加入同位素内标后,使用温水溶解,并用高氯酸沉淀蛋白质,上清液过滤后经HSS T3色谱柱分离,三重四极杆质谱仪检测,内标法定量。结果在最优化条件下,维生素B_6和生物素分别在1.0～100μg/L和0.10～10.0μg/L范围内线性关系良好,相关系数均大于0.998;定量限分别为10.0μg/100 g和1.0μg/100g。4种化合物的回收率为86.5%～97.9%,相对标准偏差为3.0%～6.6%。质控样品检测结果表明该方法准确可靠。结论该方法灵敏度高、净化效果好、定量准确,适用于婴幼儿配方乳粉中维生素B_6和维生素B_7的检测。     

高压液相色谱法检测饮料中维生素 B6

目的 建立饮料中维生素 B6 含量的高压液相色谱检测方法。方法 饮料样品经稀释、过滤后, 用高 压液相色谱仪进行测定, 测定结果与 GB/T 5009.154-2003《食品中维生素 B6 的测定》比较。结果 浓度范围 内线性关系良好, 相关系数 R 均在 0.999 以上。本方法的检出限(S/N≥3)为吡哆醇 15 μg/kg、吡哆醛 13 μg/kg、 吡哆胺 16 μg/kg。平均回收率为 98.9%~99.5%, 相对标准偏差为 0.88%~1.05%。使用高压液相色谱法测定饮料 中维生素 B6 含量与使用微生物方法检测得到的数据一致, 而高压液相色谱法所用时间比微生物法要短得多。 结论 高压液相色谱法测定饮料中维生素 B6 灵敏度高, 值得在实验室的日常检测中推广。     

高效液相色谱同时测定婴配乳粉中的七种维生素

为了同时测定婴幼儿配方乳粉中水溶性维生素硫胺素、核黄素、吡哆醇、吡哆醛、吡多胺、烟酸、烟酰胺的含量,试验建立液相色谱法。使用C18为色谱柱,以辛烷磺酸钠溶液(2 g/L)-乙腈为流动相,样品经调p H沉淀蛋白后,用超高效液相色谱高分辨率DAD检测器串联荧光检测器检测。结果表明,硫胺素、烟酸、烟酰胺、吡哆胺的检出限为5.0μg/100 g,核黄素、吡哆醇、吡哆醛的检出限为1.0μg/100 g,线性范围为0.05~5.0μg/L,线性相关系数r0.99,加标回收率为92.7%~107.6%,RSD为0.62%~3.87%。该法简单、灵敏、准确、精密,满足检测需求。     

维生素B6（之一）

维生素B6,又称为抗皮炎维生素、吡多辛、吡哆素等,是B族维生素中的一种。它属于水溶性维生素,是一组含氮的化合物,实际上是比哆类物质的通称,其中包括吡哆醇、吡哆醛、吡哆胺三种衍生物,在动物性食物内,     

HPLC-DAD/FLD测定婴幼儿配方奶粉中B族维生素及不确定度分析

建立了高效液相色谱法同时测定婴幼儿配方奶粉中维生素B2、烟酸、烟酰胺、吡哆醇、吡哆醛的方法。样品经1%甲醇的0.1%磷酸水溶液提取并沉降蛋白后,采用Thermo Hypersil GOLDTMaQ(5μm,4.6 mm×250 mm)分离,以二极管阵列检测器(DAD)和荧光检测器(FLD)串联模式检测。同时构建了不确定度评定模型,考察了不确定度的来源。结果表明,维生素B2、吡哆醇、吡哆醛在0.025～4.000μg/m L,烟酸、烟酰胺在0.125～20.00μg/m L范围内,标准曲线呈现良好的线性(R²>0.999),加标回收率在93.20%～108.00%(n=6),相对标准偏差(RSD)<8%。当婴幼儿配方奶粉中烟酸、烟酰胺含量为4 mg/100 g时,其扩展不确定度分别为0.300 mg/100 g(k=2)、0.182 mg/100 g(k=2);当吡哆醇、吡哆醛、VB2含量为800μg/100 g时,其扩展不确定度为100μg/100 g(k=2)、71.5μg/100 g(k=2)、41.9μg/100 g(k=2),其不确定度主要来源...     

强化淀粉类食品中7 种水溶性维生素的快速测定

建立高效液相色谱-二极管阵列-荧光联用法同时检测营养强化淀粉类食品中7 种水溶性维生素含量的方法。样品经淀粉酶60 ℃酶解45 min,调pH值提取后,经十二烷基硫酸钠（5 mmol/L,加入0.1%磷酸,三乙胺调pH 3.0）-乙腈梯度洗脱,VB1、烟酸、烟酰胺在不同波长下进行检测,VB2、吡哆醛、吡哆醇、吡哆胺采用目标物出峰时间段转变激发、发射波长检测。7 种维生素在各自线性范围内线性关系良好,相关系数r2为0.999 6～0.999 9,加标回收率为90.5%～102.5%,检出限为0.01～0.08 mg/100 g,定量限为0.025～0.26 mg/100 g。方法快速、高效,适用于大批量强化淀粉类食品中7 种水溶性维生素的同时测定。     

高效液相色谱法测定贵州不同产地大米中维生素B1含量

建立高效液相色谱法测定贵州不同产地大米中的维生素B1含量。大米样品粉碎后经0.1 mol/L盐酸溶液酸解、超声提取等前处理手段,采用C18色谱柱（4.6 mm×250 mm,5 μm）,以0.05 mol/L磷酸二氢钾∶甲醇=96∶4为流动相,流速1.0 ml/min,应用紫外检测器在280 nm波长下测定维生素B1含量。结果表明,维生素B1在0.2~1.0 μg/ml质量浓度范围内具有良好线性关系（R=0.999 4）,最低检出限为2 ng/ml,在低、中、高三个水平下的加标回收率为95.8%~98.7%,相对标准偏差(RSD)为0.3%~1.4%。在5种贵州不同产地的大米中,维生素B1含量较高的是湄潭县“茅贡牌”大米,含量高达0.51 mg/（100 g）。该方法样品前处理简便、灵敏度高、适用范围广,可作为谷物中维生素B1含量的一种快速检测方法。     

HPLC法同时测定婴幼儿配方奶粉中5种水溶性维生素

建立了同时测定婴幼儿配方奶粉中烟酸、烟酰胺、泛酸、维生素B2、维生素B6(包括吡哆醇、吡哆醛和吡哆胺)等5种水溶性维生素的高效液相色谱测定法.采用Zorbax SB-C8(5um,4.6 mm×250mm i.d)反相色谱柱,以质量浓度为1 g/L辛烷磺酸钠:甲醇(95:5,体积比,调pH值为3.0)+乙腈为流动相(梯度洗脱),流速为1.0 mL/min,进样量20μL.方法定量限0.5～5.0 mg/kg,加标回收率91.2%～104.2%,相对标准偏差为0.31%～3.07%.该法具有样品预处理简单,灵敏度高,分析时间短等优点,适用于婴幼儿配方奶粉中上述5种水溶性维生素的同时测定.     

HPLC-UV法测定植物甾醇中3种甾醇单体的含量

本文建立了一种利用紫外高效液相法(HPLC-UV)测定植物甾醇中菜油甾醇、豆甾醇和β-谷甾醇的方法。采用 Waters Symmetry C₁₈柱(4.6 mm×250 mm,5 μm),以乙腈和水为流动相等度洗脱,柱温30 ℃,流速1.0 mL/min,紫外检测波长为208 nm。实验结果表明:菜油甾醇、豆甾醇和β-谷甾醇在38 min内均能实现基线分离,线性范围分别为2.52~50.30、5.08~101.60、5.10~102.00 μg/mL时,甾醇单体的线性关系良好,相关系数r分别为0.9971、0.9989、0.9991,检测限为2.5 μg/mL;日内精密度在0.06%~3.06%范围内,日间精密度介于1.56%~6.61%;加样回收率介于92.74%~106.25%之间。本方法能够准确测定4种植物甾醇中3种甾醇单体的含量,其中大豆甾醇和木甾醇中3种甾醇单体的含量组成差异较大,大豆甾醇中菜油甾醇和豆甾醇的含量分别为163.80~251.23 mg/g和134.89~235.04 mg/g,远高于木甾醇中的菜油甾醇和豆甾醇含量,而木甾醇中β-谷甾醇含量为(685.10±7.55) mg/g,则明显高于β-谷甾醇在大豆甾醇中的含量。相对现有的高效液相方法,本方法实现了对混合甾醇中菜油甾醇、豆甾醇和β-谷甾醇3种甾醇单体的精确定量分析。     

婴幼儿奶粉7种维生素检测预处理条件的优化

建立了高效液相色谱法测定婴幼儿配方奶粉中烟酸、烟酰胺、泛酸、盐酸吡哆醛、盐酸吡哆醇、盐酸吡哆胺和抗坏血酸7种水溶性维生素快速简便的预处理方法。该方法用质量浓度为100 g/L的偏磷酸溶液对样品中7种水溶性维生素进行提取。检测结果的相对标准偏差在1.93%~3.21%,回收率在96.2%~103.0%,在置信度为95%时,该方法与国标方法的检测结果无显著差异。实验结果表明,该方法操作快速简便,降低了检测成本,提高了工作效率。     

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