卷烟中砷、铅、铬、镉、镍的石墨炉原子吸收测定

建立了微波消解-石墨炉原子吸收法测定卷烟中重金属元素As、Pb、Cr、Cd、Ni的方法,检测了全国10种不同牌号卷烟中的上述重金属元素含量。结果表明,As、Pb、Cr、Cd、Ni的较适宜的灰化温度和原子化温度分别为:1 400、700、1 300、600、1 000℃和2 100、1 750、2 000、1 300、2 150℃;As、Pb、Cr、Cd、Ni的平均回收率分别为97.3%、98.9%、101.2%、100.1%、102.6%;RSD分别为4.6%、3.0%、3.6%、2.2%、3.3%;检出限分别为0.147、0.265、0.146、0.026、0.172μg/L。所测卷烟样品中的5种元素含量分别为As:0.101～0.900μg/支,Pb:1.258～2.119μg/支,Cr:0.129～0.680μg/支,Cd:0.616～2.012μg/支,Ni:0.380～0.801μg/支。     

石墨炉原子吸收法测定食品中六价铬

建立食品中Cr(Ⅵ)的测定方法。方法 以10%的盐酸作为浸提液,样品通过微波120℃浸提15min,提取液经Waters MAX小柱(500mg,6cc)分离后用5%氨水淋洗,然后将淋洗液定容,经石墨炉原子吸收法间接测量Cr(Ⅵ)含量。结果 该方法在1～10μg/L的线性范围内具有良好的线性关系,r＞0.999,方法检出限为0.0087mg/kg,回收率均在90.24%～108.06%之间,RSD为3.19%～6.01%。结论 该方法简便、快速、灵敏和准确,适合蔬菜、水果、谷物以及保健食品中Cr(Ⅵ)的检测。     

接装纸中镉、铬、镍的石墨炉原子吸收光谱测定

建立了微波消解-石墨炉原子吸收法测定烟用接装纸中镉(Cd)、铬(Cr)、镍(Ni)含量的方法,并采用该方法测定了44个牌号接装纸样品中的Cd、Cr、Ni含量.结果表明:①Cd、Cr、Ni元素的平均回收率分别为102.2%、101.9%和102.2%;RSD分别为4.40%、3.96%和4.71%;检出限为0.009、0.014、0.016 mg/kg;②所测接装纸样品中Cd的含量都在1 mg/kg以下,约23.7%接装纸样品的Cr含量超过15 mg/kg,只有1个样品的Ni含量超过5 mg/kg.     

流动注射偶合化学发光法快速测定食品塑料袋中可浸出有机化合物的总量

建立一种食品包装袋中可浸出有机物质总量的新型分析方法。以食品塑料袋为样品,经超声波浸提后,用微波压力密闭快速消解浸提液,利用鲁米诺- 过氧化氢- 铬偶合流动注射化学发光体系进行测定。结果表明：有机物相当于铬(Ⅲ)的线性范围为1.154×10-10～1.154×10-5mol/L(1/3Cr3+),铬(Ⅲ)检出限为4.476×10-11mol/L(1/3Cr3+),RSD 为3.1%(n=3)。该法灵敏度高,操作简便、测定快速、成本低廉,利于普及推广。     

纳米TiO_2富集分离石墨炉原子吸收法同时测定食品中铅、镉和铬

以石墨炉原子吸收为检测手段,分别研究了纳米TiO2对金属Pb、Cd和Cr的吸附性能,并考察了吸附和洗脱的主要影响因素。结果表明：在pH值6～8范围内,纳米TiO2对金属Pb、Cd和Cr具有良好的吸附性,吸附率达到90%以上,0.5mol/L硝酸即可将纳米TiO2吸附的Pb、Cd和Cr完全洗脱。在优化的试验条件下,静态吸附量分别为Pb 15.9mg/g、Cd 36.7mg/g和Cr 65.4mg/g。其检出限（3σ）分别为6.24 x10-14g、2.02x10-13g和1.47 x10-13g,RSD分别为3.18%～5.10%、1.55%～4.04%和2.72%～3.46%,富集倍数分别为75、50和25倍,加标回收率分别在96.1%～105.6%、97.7%～99.9%和92.5%～97.8%。用于实际食品中Pb、Cd和Cr的测定,证明该方法是十分有效的。     

氮硼共掺杂碳量子点的制备及其对六价铬的检测

目的 建立一种基于荧光碳量子点的快速检测方法,定量检测饮用水和食品中的六价铬[hexavalent chromium, Cr(Ⅵ)]。方法 以无水柠檬酸和3-氨基苯硼酸分别作为碳、氮和硼源,通过一步水热法合成氮硼共掺杂碳量子点(nitrogen-boron-doped carbon quantum dots, N,B-CQDs),基于荧光内滤效应对Cr(Ⅵ)进行检测。结果 在优化后的最佳检测条件下, N,B-CQDs对Cr(Ⅵ)在0.01～10.00 mg/L内呈现良好的线性关系,检出限低至3.81μg/L,表现出选择性好、灵敏度高等特点。将此方法应用于饮用水、白醋和虾皮中Cr(Ⅵ)含量的测定,加标回收率在85.8%～112.3%之间,相对标准偏差低于5%。结论 本研究制备的N,B-CQDs在Cr(Ⅵ)检测方面具有检出限低、灵敏度高、选择性好等优点,可以为Cr(Ⅵ)快速检测提供一定的理论和技术参考。     

食品中Cr(Ⅲ)和Cr(Ⅵ)分离及ICP-MS法测定研究

本文报道了食品中Cr(Ⅲ)和Cr(Ⅵ)分离并用ICP-MS仪进行测定方法．食品经微波消化后，用离子交换树脂进行交换，以^45Sc为内标元素，采用内标法进行测定。该方法加标回收率是98．6％-99．6％，相对标准偏差RSD是2．1％～3．5％，检测限是0．006-0．01ng／ml，可用于食品以及饮用水、废水中Cr(Ⅲ)和Cr(Ⅵ)的测定。     

金属元素自动分析仪测定铬鞣剂中痕量Cr(Ⅵ)的研究

提出了自动参比流动注射法 ,对铬鞣剂中的痕量Cr(Ⅵ )的测定。采用ZJ- 1a金属元素自动分析仪的流动注射功能 ,以二苯碳酰二肼、丙酮、硫酸的混合溶液为显色剂 ,丙酮的硫酸溶液为参比溶液 ,对铬鞣剂中的痕量Cr(Ⅵ )进行了测定。考察了显色剂中二苯碳酰二肼浓度、显色剂中酸的种类及浓度、流速等因素的影响 ,优化了试验条件。在优化的试验条件下 ,测得Cr(Ⅵ )的检出限为 0 .2 8× 10 -9g/mL ,相对标准偏差为 1.2 4 % ,对铬鞣剂中的Cr(Ⅵ )进行分析 ,回收率在 96 .1%～ 10 3% ,结果令人满意     

恒电流库仑法测定制革废水中铬(Ⅵ)

研究了恒电流库仑法测定制革废水中微量 Cr( )的方法及条件。在 3.5 mol/ L H2 SO4- 6 .0 mg/ m L Ce2(SO4) 3 - 0 .0 15 mol/ L Fe NH4(SO4) 2 - H3 PO4电解液中 ,加入 1- 2滴 Ag NO3 ,在快速搅拌下完成反应 ,用平衡电位法指示终点。测定 0 .5 ︼g和 1.0 - 10 0 .0 ︼g Cr( ) ,相对误差分别小于± 1.5 %和± 1.0 % ,标准偏差分别小于 0 .0 2和 0 .4。该法测定结果与比色法对照 ,结果基本一致     

应用X-5大孔吸附树脂测定深色革Cr(Ⅵ)含量的研究

建立了以X-5大孔吸附树脂为脱色剂,依据IUC-18标准来测定深色革中Cr(Ⅵ)含量的方法。试验表明:对深色革提取液脱色率可达90%,而对Cr(Ⅵ)吸附率小于5%,当Cr(Ⅵ)浓度在3.368~33.68μg/L范围时,回归方程C=-0.1817+584.4△A(r=0.9999)。样品加标回收率为91.3%~96.2%,相对标准偏差为3.59%~6.85%。     

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