气相色谱法测定配方奶粉中的脂肪酸和反式脂肪酸

建立同时测定配方奶粉中脂肪酸和反式脂肪酸的气相色谱分析方法。样品中的脂肪酸和反式脂肪酸经乙酰氯-甲醇甲酯化处理后,用气相色谱仪测定,采用HP-88色谱柱分离定性,以十一碳酸甘油三酯为内标进行定量。结果表明:顺-反异构体脂肪酸分离效果较好,脂肪酸和反式脂肪酸的回收率在97.2%～104.6%之间,相对标准偏差小于3.5%,检出限为5μg/g。     

气相色谱法测定奶茶中的反式脂肪酸

选取我国市场上常见的品牌奶茶,采用气相色谱法测定8种奶茶产品、7种奶精及20种果粉中的反式脂肪酸组成。结果表明:一杯300mL的奶茶,其反式脂肪酸量在0.5～3.0g之间,奶精中反式脂肪酸含量最高可达8.6g/100g,果粉含量则在1.0～2.2g/100g之间;奶茶中反式脂肪酸主要来自奶精与果粉,以反式C18脂肪酸为主,其中一烯含量最多、二烯含量较少、反式C16脂肪酸甚微。奶茶、奶精及果粉中的反式脂肪酸含量普遍偏高,不同类型、不同品牌的奶茶间和不同口味的果粉间反式脂肪酸含量存在显著性差异。     

气相色谱法测定氢化油脂加工食品中反式脂肪酸含量

目的建立气相色谱法测定氢化油脂加工食品中反式脂肪酸含量的分析方法。方法采用HP-88毛细管石英柱(30 m×0.25 mm×0.20μm)分离定性和定量43种饱和脂肪酸、不饱和脂肪酸,并应用于市售饼干、糕点、冰淇淋、奶茶、巧克力、咖啡等加工食品中的反式脂肪酸含量测定。结果顺、反式脂肪酸在30 m长的毛细管石英柱分离情况良好,各反式脂肪酸在3~100μg/m L浓度范围内TFA线性良好(R≥0.9990),重现性好(RSD6%),回收率85.3%~91.8%,检测限为0.01 g/100 g;其分离速度较100 m长的毛细管石英柱提高了1倍;奶油蛋糕、炼奶起士、饼干类含有的反式脂肪酸含量较高,且以反式棕榈油酸(t-C16:1)、反式油酸(t-C18:1)为主。结论该方法快速、准确、分离良好,可作为检测氢化油脂加工食品中反式脂肪酸含量的推广方法。     

3类非预包装食品中反式脂肪酸含量的测定

目的：对常见的3类非预包装食品（奶茶、油炸食品、奶油蛋糕）中6种反式脂肪酸进行测定,比较其反式脂肪酸含量的高低。方法：参照《食品安全国家标准食品中反式脂肪酸的测定》（GB 5009.257—2016）,采用气相色谱法对样品中的6种反式脂肪酸含量进行测定。采用非参数检验对实验结果进行统计分析。结果：3类非预包装食品的反式脂肪酸含量差异具有统计学意义（P <0.05）。奶茶中反式脂肪酸平均含量为（0.05±0.02）g/100 g;油炸食品中反式脂肪酸平均含量为（0.41±0.21）g/100 g;奶油蛋糕中反式脂肪酸平均含量为（1.58±0.32）g/100 g。油炸土豆与油炸鸡肉反式脂肪酸含量差异无统计学意义（P>0.05）。结论：3类非预包装食品中奶油蛋糕的6种反式脂肪酸含量最高,奶茶的6种反式脂肪酸含量最低;油炸鸡肉与油炸土豆的6种反式脂肪酸含量与其物料种类无关。     

自动顶空-气相色谱-串联质谱法测定生乳中8种苯系物的研究

建立生乳中8种苯系物同时测定的自动顶空-气相色谱-串联质谱法。 方法 试样中的苯系物经顶空进样器加热挥发后进入HP-InnoWax（30m*0.25mm,0.25μm）毛细管色谱柱进行分离,气相色谱质谱联用仪进行测定,外标法定量。 结果 8种苯系物在0-25.6ng/mL浓度范围内线性良好,相关系数大于0.99,,定量限为0.1-0.8μg/kg、回收率为85.0%～106.8%、精密度均小于7%。 结论 本方法前处理简单、灵敏度高,可以满足生乳中8种苯系物的同时测定要求。     

ASE-HPLC柱后衍生荧光检测法测定水产品中8种磺胺类

为了开发一种采用ASE萃取、色谱柱分离后衍生并液相色谱荧光检测测定水产品中8种常用磺胺类药物残留的方法,试验采用南美白对虾等水产品通过加快溶剂萃取仪提取后,稀盐酸反萃取,正己烷去脂,Waters Xterra RP-C18色谱柱分离,荧光胺衍生后被荧光检测器检测,外标法定量。结果显示,8种磺胺类线性关系在0.01~1.0 mg/L范围内,相关系数0.999以上;方法回收率为78.9%~98.6%,相对标准偏差1.0%~13.4%;当取样质量为2.50 g时,检出限为5~20μg/kg,定量限为15~60μg/kg。     

棉花中7种烟碱类农药残留的液相色谱-串联质谱法测定

应用液相色谱-电喷雾电离三级四极杆串联质谱(LC-ESI-MS/MS)仪器,建立测定棉花中7种烟碱类农药残留的检测方法。样品先添加同位素内标吡虫啉-D4,再用乙腈超声提取、浓缩,乙腈-甲酸(0.15%)溶液溶解,以ZORBAX Eclipse XDB-C8色谱柱为分离柱。液相色谱-串联质谱仪采用正离子扫描方式,多反应监测,每种烟碱类农药各选2对离子进行定性、定量分析,除吡虫啉外均采用外标法定量。在0~12.5μg/L测定范围内此方法具有良好的线性关系(r0.99),在10、20和40μg/kg 3个水平进行添加回收实验,平均回收率范围为75.9%~98.4%;相对标准偏差小于15.8%;方法检测低限(LOQ)均为10μg/kg。     

QuEChERS-GC-MSMS法测定大米中20种农药残留

建立一种简便、快速、灵敏可同时测定大米中20种农药残留的分析方法。采用乙腈溶液提取大米样品中的农药,经Qu Ech ERs方法净化,采用气相色谱分离,多反应监测(MRM)模式进行测定。通过保留时间、选择离子及其相对丰度定性,外标法定量。结果表明,20种农药的线性范围为0.01μg/m L~0.2μg/m L,线性相关系数大于0.99,大多数农药的加标回收率在70%~120%之间,相对标准偏差小于20%。     

超高效液相色谱法快速测定饮料中13种常见的食品添加剂

目的建立超高效液相色谱法(ultra performance liquid chromatography,UPLC)测定水果茶饮料中常见的13种防腐剂、甜味剂和着色剂的分析方法。方法样品经超声加热除去二氧化碳或乙醇后稀释、离心、过滤后直接进样,采用Agilent ZORBAX Eclipse Plus C_(18)(50 mm×2.1 mm,1.8μm)色谱柱分离,以甲醇-乙酸铵(0.02 mol/L)为流动相进行梯度洗脱,柱温28℃,流速0.5 mL/min,采用二极管阵列检测器切换波长分析,外标法定量。结果 13种待测成分在6 min内良好分离,质量浓度在0.05～10μg/mL范围内线性良好,相关系数r~2均大于0.999;定量限为0.010～0.025μg/mL;平均加标回收率在92.1%～101.0%之间;重复性和精密度RSD(n=6)在5.0%以内。结论该方法快速、准确,适合用于饮料中13种防腐剂、甜味剂、合成着色剂定性、定量测定。     

食用油中反式脂肪酸的气—质分析法研究

建立气相色谱—质谱法测定食用植物油中反式脂肪酸的分析方法。食用植物油中的脂肪酸甲酯化后,经强极性毛细管柱SP—2560分离,采用质谱全扫描Scan方式得到各组分质谱图与标准谱库做相似度检索来定性,面积归一化法定量。用所建立的方法测定了6种常见食用植物油中反式脂肪酸含量,该法测定食用植物油中的反式脂肪酸含量前处理简单、快...     

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