流动分析仪快速检测啤酒发酵液二氧化碳

为了更快捷、更精确的测定啤酒发酵液中二氧化碳的含量,使用连续流动化学分析仪对已知样品进行了测定.在0.15 g/100 mL～0.75 g/100mL浓度范围内,具有良好的线性关系(R=0.999 95)和重现性(RSD范围为0547％～1.078％),空白加标回收率较准确(98.667 ％～101.333％),并具有较低的检出限(0.005 mg/L).因此该方法可作为一种批量、快速、准确、环境友好的检莉方法应用于生产.     

离子色谱同时测定烟草中的七种无机阴离子

建立了超声波提取样品,离子色谱法同时测定烟草中的七种无机阴离子的方法.系统的研究了超声波提取样品,RP前处理柱去除样品基体中共存组分对测定的干扰,淋洗液浓度,流速的最佳实验条件.该方法的检出限为0.002 0 mg/L～0.206 9 mg/L,相关系数为0.998 7～0.999 9,相对标准偏差(RSD)为0.54 ％～13.01％,加标回收率为92.10％～107.18％,符合测试要求.实验表明该方法具有分析时间短,线性范围宽,灵敏和准确,简单和快速,试剂用量少等优点.     

自动化学分析仪快速检测大曲糖化力方法研究

为了更快捷、更精确的测定大曲的糖化力,选用葡萄糖作为标准品,使用流动化学分析仪对已知样品进行了测定.在5.2mg/(mL·h)～31.2mg/(mL·h)浓度范围内,具有良好的线性关系(R=0.99997)和重现性(RSD范围为0.195%～0.328%),空白加标回收率较准确(99.68%～104.24%),并具有较低的检出限[4.996×10-2mg/(mL·h)].因此该方法可作为一种快速、准确的检测方法应用于生产.     

植物油中角鲨烯的提取与高效液相色谱法分析

建立了硅胶柱提取,高效液相色谱法分析植物油中角鲨烯的方法.样品用石油醚溶解,过硅胶柱净化,经C18柱分离,紫外检测(210 nm).结果表明,角鲨烯与其他杂质峰得到良好分离,在2～1 000 mg/L浓度范围内,峰面积与浓度呈良好线性,线性相关系数(R2)0.998.在大豆油中添加5.0、100、500和1 000mg/kg水平的角鲨烯,平均加标回收率为82.4％～ 89.3％,相对标准偏差小于7.1％(n=8),方法测定低限(LOQ)5 mg/kg.本方法准确、灵敏、可靠,已应用于实际样品分析.     

纺织品中苯乙酮增塑剂的检测方法

建立了测定纺织品中苯乙酮增塑剂的气相色谱-质谱法.样品使用甲基叔丁基醚在超声波中萃取,萃取液过滤、合并、浓缩后净化,进行气相色谱-质谱分析.结果显示,该方法检出限为0.3 mg/kg,定量限为0.9 mg/kg.对样品进行3组浓度水平的加标测定(N=6),平均回收率为80％ ～ 120％,相对标准偏差(RSDr)≤8％.在0.64 ～ 82 mg/kg范围内线性关系良好,相关系数r =0.9999.该方法简便、快速、准确,可应用于纺织品中苯乙酮增塑剂含量的测定.     

固相萃取-高效液相色谱法检测油炸薯条中丙烯酰胺

目的 建立了一种采用固相萃取-高效液相色谱(SPE-HPLC)测定油炸薯条中丙烯酰胺的方法.方法 样品用2.0 mol/L氯化钠溶液进行提取,使用Styre Screen H2P固相萃取柱(200 mg/3 ml)净化,然后用Sapphire C18反相色谱柱进行分析,流动相为甲醇/水(5∶95),流速为1.0 ml/min,检测波长为200 nm.结果 在1.0 ～ 10.0 μg/g的添加水平范围内,样品中丙烯酰胺的平均回收率为66.2％ ～80.9％,相对标准偏差为1.6％ ～2.1％,最低检测限和最低定量限分别为0.025和0.080 μg/g.结论 该方法操作简单、快速、准确,可用于油炸薯条中丙烯酰胺的快速测定.     

微波消解-电感耦合等离子体质谱法测定豆类中的锶

本研究建立了微波消解样品-电感耦合等离子体质谱法测定豆类中锶含量的方法。在选定的实验条件下,方法在0.01mg/L～0.30mg/L范围内呈良好的线性关系(r=1.0000),测得最低检出限为0.08ng/g,相对标准偏差为0.9～3.5%,回收率为90.0～98.0%。本方法具有操作简单、快速、灵敏度高、抗离子干扰能力强的优点,适用于快速准确测定豆类中的锶元素。     

气相色谱-串联质谱法测定酒中氨基甲酸乙酯的含量

建立利用气相色谱-串联质谱仪测定酒中氨基甲酸乙酯的方法.样品经二氯甲烷提取后,采用DB-225MS毛细管柱分离样品,以GC/MS/MS测定氨基甲酸乙酯的含量,结果表明,该方法线性范围为10～1000 μg/L,方法检出限为1.0 μg/L,标准加入5～250 μg/L的平均回收率为78.00％～81.20％.本方法具有操作简便、快速、准确等优点,可用于酒中氨基甲酸乙酯的检测.     

书刊中双酚A的检测方法研究

本文采用高效液相色谱分离检测(荧光检测器),建立书刊中双酚A的测定方法。采用甲醇作为提取溶剂,通过优化提取方式(恒温水浴振荡提取或超声提取)、流动相的比例(甲醇与水),寻找最优的试验方案。双酚A在0.02mg/L～1.00mg/L范围内有较好的线性,相关系数达到0.999以上,方法检出限及定量限分别为0.004mg/L、0.02mg/L。不同加标水平的回收率在93%～102%,同一样品重复测试10次,其相对标准偏差小于1.5%,不同样品重复测试10次,其相对标准偏差小于2.2%。本文研究方法能够准确提取和测定书刊中的双酚A。     

QuEChERS-HPLC快速测定食品中七种食用合成色素

建立了一种同时测定豆制品和肉制品中7种食用合成色素(柠檬黄、日落黄、胭脂红、苋菜红、亮蓝、偶氮玉红、诱惑红)的QuEChERS-HPLC方法.样品采用乙醇-氨水-水(7∶2∶1)超声提取,混合使用C18和乙二胺-N-丙基硅烷(PSA)两种基质分散净化剂净化,浓缩后采用SunFireTMC18色谱柱(250mm×4.6mm,5μm)分离.以甲醇-20mmol/L乙酸铵水溶液为流动相,梯度洗脱,流速为1mL/min,测定波长410nm和520nm.实验通过空白基质溶液稀释标准品建立校正的标准曲线,以消除基质效应.结果表明,7种食用合成色素在0.5～10μg/mL线性范围内具有良好的线性关系(相关系数0.9971～0.9999),样品加标回收率为83.01％～ 108.84％,相对标准偏差为4.53％～15.23％,方法的检出限在0.1～0.3mg/L之间,定量限在0.3～0.4mg/kg之间.方法操作简便、快速、准确,可满足豆制品和肉制品中食用合成色素的分析要求.     

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