不同消化方法对大蒜中锰、锌、铜、镉含量的影响

目的：研究不同消化方法对大蒜中Mn，Zn，Cu争Cd微量元素含量的影响。方法：采用干法灰化争湿法消化预处理大蒜，干法灰化以时间争温度做单因素实验；湿法消化以酸的比例、放置时间争种类做单因素实验，通过正交实验确定最佳消化条件，利用原子吸收分光光度法测定大蒜中Mn，Zn，Cu争Cd的含量。结果表明：大蒜中Mn，Zn，Cu争Cd的最佳消化条件，干法灰化是Mn450℃，4h；Zn650℃，6h；Cu550℃，4h；Cd 450℃，4h。湿法消化是Mn：HNO3：H2SO4=5l1，16h；Zn：HNO3：HCl=7：1，12h;Cu：HNO3：H2O=1：1，12h；Cd：HNO3：H2SO4=1：2，12h。测定结果的相对标准偏差均在2．0％以下，回收率为99％～101％之间。     

温室和非温室大棚番茄微量元素的对比

采用干法灰化处理样品,用火焰原子吸收光谱法连续测定了番茄中8种微量元素Mn、Bi、Cu、Cr、Ni、Pb、Zn、Fe的含量.本方法的贴D值在0.66%～1.48%之间,回收率为97.6%～112.1%.测试结果表明:番茄中Fe、Zn、Cu元素的含量较高;露天种植番茄Fe、Zn、Cu元素的含量高于温室大棚种植的番茄;对鲜果进行测定时,捣碎后建议不用纱布过滤.     

云南石屏碰柑桔子中微量元素研究

采用干法灰化处理样品,用火焰原子吸收光谱法连续测定了碰柑桔中 9 种微量元素Zn、Mn、Cu、Ni、Fe、Cr、Cd、Co、Pb 的含量;RSD值在 0.27%～4.1%之间,回收率为 101.0%～112.8%;并对测试结果进行了对比分析.发现在碰柑桔中 Fe 元素的含量在果肉、籽、果皮中的含量均较高.     

ICP-AES法同时测定不同月份香椿不同部位中的微量元素

用灰化溶解法处理试样制备测试液,用电感耦合等离子体原子发射光谱法(ICP-AES法)同时测定不同月份香椿不同部位中的Fe、Mn、Cu、Zn、Ca、Mg、Na、K、Al、Pb、Cd、和Ni12种元素的含量。该法的加标回收率在93.6%～109.0%之间,相对标准偏差RSD0.51%～4.87%,具有良好的准确度和精密度。试验结果表明:香椿中含有丰富的Ca、Mg、Fe、Zn和K等元素,Na、Mn、Cu的含量也较丰富,各元素含量随时间及部位而变化。本研究结果为香椿资源的综合利用提供科学依据。     

坩埚材质对干灰化法测定婴幼儿米粉中钠含量的影响

采用不同材质坩埚进行干灰化法前处理对婴幼儿配方米粉中钠含量测定的影响,并与湿灰化法和微波消解法进行对比分析。结果表明,采用瓷坩埚的干灰化法测定婴幼儿米粉中钠含量可使测定结果偏高,测定结果比湿法和微波处理偏大200%~300%。采用石英坩埚的干灰化法测定结果与湿灰化法和微波消解法测定结果一致;通过氢氟酸腐蚀试验发现瓷坩埚内衬表面钠析出量在(0.2~0.3)mg/cm~2范围内。推断瓷坩埚使测定结果偏高可能是由于瓷坩埚在高温下与米粉基体反应,使坩埚内衬表面钠元素向样品基体中进行了微量的迁移,从而使结果偏高。     

云南文山野生金线莲中微量元素研究

采用干法灰化处理样品,用火焰原子吸收光谱法测定野生花叶开唇兰和滇越金线兰中Zn、Mn、Cu、Ni、Fe、Cr、Cd、Co、Pb 9种微量元素的含量.结果:RSD(%)值在0.66～3.25之间,回收率为99.8%～103.7%;并对分析结果进行了对比分析,花叶开唇兰中Fe、Cu元素比滇越金线兰高,滇越金线兰中Mn、Zn、Co元素含量比花叶开唇兰的高.     

江西名茶中10种金属元素含量的测定

对K、Ca、Na、Mg、Fe、Cu、Mn、Zn 8种必需元素火焰原子吸收光谱法的最佳工作条件(乙炔流量、空心阴极灯灯流量和燃烧器高度)进行优化,对铅、镉两种有毒元素石墨炉原子吸收光谱法的最佳工作条件(灰化温度、灰化时间、原子化温度及原子化时间)进行优化,绘制各元素的标准曲线,考察方法的检出限和精密度,优化样品前处理条件及测定样品加标回收率,并对江西名茶中对应的10种金属元素的含量进行测定比较。结果表明,建立的各元素原子吸收光谱法在相应浓度区间内线性关系良好,相关系数为0.991 8～0.999 2,精密度为0.77%～3.32%,检出限为0.004～0.050μg/mL,回收率为99.25%～102.25%,均符合要求。10种金属元素在8种茶叶中的含量差异性显著,其排序基本为KMgMnCaFeNaZnCuPbCd;遂川狗牯脑中K、Ca、Fe含量最高,庐山云雾中Na含量最高,靖安白茶中Mg、Zn含量最高,井冈山翠绿中Mn含量最高,武夷红茶中Cu含量最高,8种茶叶中Pb、Cd含量均较低。试验建立的原子吸收光谱法操作简便、干扰较少、灵敏度高,适用于各种茶叶中相应元素含量的测定;8种江西名茶中K、Ca、Na、Mg 4种常量元素和Fe、Cu、Mn、Zn 4种微量元素含量都比较丰富,Pb、Cd两种有毒元素含量均低于国家标准。     

品种、种植年份和区域对烤烟中微量元素含量的影响及元素含量间的相互关系

为了明确我国不同年份、品种和种植区域烤烟中Mn,Fe,Cu,Zn,Ca和Mg含量间差异,以及烟叶中元素间相互关系,测定了2004,2005,2007和2008年全国不同品种和种植区域的烤烟C3F等级烟叶中微量营养元素含量并分析了元素含量间的相关性.结果表明:①我国烤烟中微量营养元素Cu含量的变异系数最大,Ca含量的变异系数最小.Cu和Mn含量的变异系数大于60%,Fe和Zn的变异系数在40%～50%,Mg和Ca的变异系数小于30%.不同品种系列的6种元素平均变异系数以K326系列最大,为48.46%,翠碧系列最小,为24.82%.②烤烟烟叶元素含量年际间变化大,元素含量受种植品种和种植区域等因素的影响.烤烟元素含量分布具有明显的地域性,黄淮烟草种植区的烟叶Fe,Ca和Mg含量高,东南烟草种植区的烟叶Fe,Ca和Mg含量低,Zn含量高;长江中上游烟草种植区和西南烟草种植区的烟叶Mn,Cu含量高.③烟叶中Ca和Mg含量与Mn和Zn含量呈极显著负相关;与Fe含量呈极显著正相关.     

青海不同地区牦牛乳矿物质元素含量比较研究

为探究青海省不同地区牦牛乳中矿物质元素含量的差异。在青海省6个地区共采集牦牛乳样83份，用火焰原子吸收仪测定乳中常量矿物质元素（K、Ca、Na、Mg）和微量矿物质元素（Fe、Cu、Zn、Co、Mn）含量。分析结果表明，青海省不同地区牦牛乳中9种矿物质元素含量均存在差异，以K、Ca、Cu、Co和Mn含量差异最为明显；Ca含量与Mn、Na含量，K含量与Co含量，Cu含量与Mg含量呈极显著正相关（P<0.01）;Co含量与Cu、Ca含量，Mn含量与Cu、K含量，K含量与Cu、Mg、Fe、Ca含量呈极显著负相关（P<0.01）。熵权法TOPSIS综合评价结果显示，贵南县贴合度最高为0.71，玉树州贴合度最低为0.18。因此，从矿物质元素含量角度来看，贵南县牦牛乳品质高于其余地区。     

火焰原子吸收光谱法测定海螵蛸中15种微量元素含量

用火焰原子吸收光谱法测定海螵蛸中微量元素(Ca、Mg、K、Cu、Zn、Mn、Cr、Co、Ni、Fe、Si、Al、Pb、As和Cd)的含量,并对结果进行分析比较。该方法的加标回收率为96.5%～108.7%,RSD小于2.8%,具有良好的准确度和精密度。人体必需的重要微量元素Zn、Fe、Mn、Cu含量均较高。另外,样品中还检出微量有毒元素铅、砷和镉。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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