微波消解-石墨炉原子吸收光谱法测定皮革制品及纺织品中痕量镉

研究建立了微波消解-石墨炉原子吸收光谱法测定皮革制品及纺织品中痕量镉的检验方法。样品经微波消解后,以硝酸镍为基体改进剂,试验了石墨炉原子吸收法测定镉的最佳仪器条件。在选定的最优测试条件下,镉的检出限为0.025μg/L,样品加标回收率为96.5%～105.5%,相对标准偏差小于4.4%。用于皮革制品及纺织品中痕量镉的测定,结果满意。     

微波消解-石墨炉原子吸收法测定食品污染物中铅镉的含量

目的探讨微波消解-石墨炉原子吸收法测定食品污染物铅镉的含量。方法采用微波消解技术,在阶梯升高温度和加热功率条件下,用硝酸和过氧化氢彻底消解样品,消解后的样品用石墨炉原子吸收分光光度法测定铅镉。结果铅浓度在0～20.0μg/L、镉浓度在0～10.0μg/L范围内呈良好的线性关系,相关系数铅r=0.9995,镉r=0.9997;最低检出限铅为5.0μg/kg,镉为0.10μg/kg;相对标准偏差铅5.4%,镉7.8%;回收率铅镉都在90.0%～105.0%之间。检测4类食品240份样品,其中大米(面粉)、猪肝(猪肾)、水产品、干食用菌铅合格率分别为86.5%、77.5%、81.5%、87.5%,镉合格率分别为82.0%、76.5%、90.0%、88.0%。结论该方法能够满足食品污染物中铅镉的分析要求。     

微波消解-石墨炉原子吸收法测定土壤中的铅、镉和银

将土壤样品经微波消解前处理后,采用石墨炉原子吸收法对土壤中的铅、镉、银进行分析。本方法具备操作简便、检出限低、精密度和准确度高等优点,适用于土壤中铅、镉、银等金属含量的测定。     

不同前处理-石墨炉原子吸收光谱法检测红葡萄酒中铅

对不同红葡萄酒前处理方法进行了研究,建立了石墨炉原子吸收检测红葡萄酒中铅含量的方法。红葡萄酒分别用直接稀释、蒸发浓缩、H2O2-HNO3消解、HClO4-HNO3消解和微波消解等5种前处理方法进行消化处理,以抗坏血酸,磷酸二氢铵,硝酸镁,氯化钯作为基体改进剂,研究选择基体改进剂合适种类及用量,对石墨炉检测法的测定条件进行研究。结果表明最佳基体改进剂为抗坏血酸,吸入量为5μL。直接稀释、蒸发浓缩、H2O2-HNO3消解、HClO4-HNO3消解和微波消解5种不同前处理的相对标准偏差5%左右,微波消解的RSD(%)为3.2。微波消解-石墨炉原子吸收光谱法检测红葡萄酒中铅,该方法快速简单、精密度和准确度高,是红葡萄酒中铅含量测定的理想方法。     

混合基体改进剂-石墨炉原子吸收光谱法测定 速溶茶中的铅镉铬

目的以微波消解为前处理方式,建立一种石墨炉原子吸收光谱法测定速溶茶中微量重金属铅、铬、镉的实验方法。方法采用高压密闭微波消解仪对速溶茶进行消解,加入硝酸铵、硝酸钯等基体改进剂消除样品干扰,并优化仪器条件进行石墨炉原子法测定。结果测定速溶茶中铅、铬、镉的最佳基体改进剂分别为硝酸铵-硝酸钯混合基体改进剂、硝酸钯基体改进剂、硝酸铵-硝酸钯混合基体改进剂。在最佳实验条件下,铅、铬、镉的线性范围分别为0~80μg/L、0~40μg/L、0~2μg/L,检出限分别为0.3681μg/L、0.1268μg/L、0.0076μg/L,铅、镉、铬的标准曲线相关系数分别为0.9990、0.9978和0.9992,回收率均在98.64%~101.9%之间,样品测定相对标准偏差均小于5%。结论该方法简便、快速、准确,可作为速溶茶中铅、镉、铬快捷、可靠的检测方法。     

微波消解-石墨炉原子吸收分光光度法测定猪肉中镉

建立了微波消解-石墨炉原子吸收法测定猪肉中镉,用微波消解法代替传统的电热板加热对猪肉中镉进行湿法消解,该方法操作简单,实用性强,整个消解过程减少了人工的繁琐步骤。通过优化微波消解条件和石墨炉原子吸收测定条件,在0.0~3.0ng/m L范围内,曲线相关系数达到(r=0.9990)时,方法检出限量为0.001mg/kg,相对标准偏差在1.3%~2.2%之间,加标回收率在97.1%~99.3%之间。与传统的湿法消解相比,微波消解所得到的分析结果的准确性、可靠性和精密度都较为理想。     

石墨炉原子吸收法测定棉纺织品铅镉效果探讨

探讨微波消解石墨炉原子吸收光谱法测定纯棉纺织品中铅和镉的效果.将市售的几种纯棉纺织品样品进行了微波消解,而后通过石墨炉原子吸收光谱法测定其铅和镉的总含量.试验数据表明:该法对铅的检出限为40.0 μg/kg,对镉的检出限为1.3 μg/kg;相对标准偏差小于10％;铅和镉的加标回收率分别为95.2％与106.3％.认为该法适用于纯棉纺织品中铅和镉的定量测定,且具有简便易行,准确可靠等优点.     

微波消解-石墨炉原子吸收分光光度法测定味噌中的微量铅

目的:建立了微波消解-石墨炉原子吸收分光光度法测定味噌中铅含量的方法.方法:味噌样品以硝酸及过氧化氢作为溶剂,用微波消解仪消解,且以磷酸氢二铵为基体改进剂,以原子吸收分光光度法测定其中铅的含量.结果:味噌中微量铅的检出限为0.005 mg/kg,相对标准偏差＜2.4％,回收率为95.5％～103.1％.结论:此方法简便、快速、准确,适合测定味噌中的微量铅.     

微波消解-石墨炉原子吸收法测定果汁中铅和镉

应用具有温度传感器附件的Ethos1型微波消解仪处理果汁样品,并采用石墨炉原子吸收法对其中铅、镉含量进行测定。对消解试剂和微波消解条件进行了筛选和优化,研究了石墨炉原子吸收的测定条件。研究表明,以HNO3-H2O2(7∶1,V/V)作为微波消解试剂,180℃,1 200W,消解8min最佳。在基体改进剂NH4H2PO4存在下,可有效地消除基体的影响,建立了微波溶样原子吸收光谱法测定果汁中Pb、Cd的方法,其Pb和Cd的检测限分别为6.0μg/L和1.0μg/L。将该法应用于果汁样品中Pb、Cd的测定,结果令人满意,RSD小于5.0%,Pb回收率为78.7%～102.4%,Cd回收率为97.8%～108.7%。通过试验,提出在微波消解前,在电热消解仪上进行预消解(140℃,20min),增大了称样量,显著降低了方法的检出限。微波消解法处理果汁样品,具有快速、简便、节约试剂、消解完全等特点,测定结果的精密度、准确度令人满意。     

钯基体改进剂-石墨炉原子吸收光谱法测定茶叶中的铅和镉

目的建立石墨炉原子吸收光谱法测定茶叶中的痕量铅和镉。方法采用湿法消解对茶叶样品进行消解,加入氯化钯、硝酸镁、磷酸二氢铵作为基体改进剂扣除样品中背景干扰的影响,并优化仪器条件进行石墨炉原子光谱法测定。结果测定茶叶样品中铅的最佳基体改进剂为氯化钯-硝酸镁,测定镉的最佳基体改进剂为磷酸二氢铵+硝酸镁。铅优化后的条件为:灰化温度为900℃、原子化温度2000℃,镉优化后的条件为:灰化温度为700℃,原子化温度1100℃。结论本方法简便、快速、准确,可适用于茶叶样品中铅、镉的分析。     

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