电感耦合等离子体质谱法测定面粉中铝

建立了电感耦合等离子体测定面粉中铝含量的方法。样品经加酸微波消解赶酸后,用电感耦合等离子体质谱仪进行测定。标准曲线线性范围内线性相关性不小于0.999,最低检出限为0.03 mg/kg,加标回收率为87.2%~96.2%,精密度为0.43%~1.01%。本方法操作简单、灵敏度高、回收率好。     

ICP-OES法测定婴幼儿配方奶粉中钼的方法研究

建立电感耦合等离子体发射光谱法测定婴幼儿配方奶粉中的钼含量。此方法用微波消解法处理婴幼儿配方奶粉样品,然后运用电感耦合等离子体发射光谱法分析样品,同时探讨最佳消解奶粉样品和分析样品的条件。微波消解-电感耦合等离子体光谱法测定婴幼儿配方奶粉中的钼,方法在0~0.500 mg/L范围内线性关系良好(0.999 9),检出限可以达到0.048 mg/kg,6次奶粉样品测定结果的相对标准偏差小于3%;在加标量为0.2、1.0、2.0 mg/kg 3种梯度浓度下,回收率在96.6%~102%之间;标准参考物质的分析结果也在证书值范围内。该方法使用试剂少,空白值低,具有良好的精密度和准确度,适用于婴幼儿配方奶粉中钼的测定。     

电感耦合等离子体质谱法测定海鱼中6种重金属含量

目的建立电感耦合等离子体质谱法测定海鱼中6种重金属的检测方法。方法样品用硝酸溶液微波消解进行前处理,采用电感耦合等离子体质谱法对样品中6种重金属进行测定。结果各元素在0~1.0 mg/L范围内呈良好的线性关系,相关系数均>0.999。方法检出限为铅:2.5μg/kg,镉:0.3μg/kg,汞:2.5μg/kg,砷:12.5μg/kg,铬:10μg/kg,镍:13μg/kg。回收率为92.4%~101%,相对标准偏差为2.1%~4.5%。结论该方法具有较高灵敏度、准确度及精密度,适用于海鱼中6种重金属元素的测定。     

微波消解-电感耦合等离子体质谱法测定面料中的锗含量

电感耦合等离子体质谱法具有灵敏度高、速度快、线性范围宽等优点,可用于面料中微量元素的测定。通过微波消解法消解纺织面料,采用电感耦合等离子体质谱法(ICP-MS)测定纺织面料中的锗含量,建立了微波消解-电感耦合等离子体质谱法测定面料中锗元素含量的方法。研究结果表明,锗元素在0.2~40.0μg/L范围内线性关系良好(R2=0.999 9),方法的检出限为0.02 mg/kg,不同含量加标(0.02、0.04、0.08、0.16 mg/kg)回收率在82.6%~107.8%,相对标准偏差3.0%~9.3%(n=6)。该方法具有灵敏度高、精密度好、检出限低的优点,能够用于面料中锗元素含量的测定。     

比较微波消解-原子荧光法和电感耦合等离子体质谱法测定饲料中总砷

目的对比微波消解-原子荧光法和电感耦合等离子体质谱法测定饲料中总砷含量。方法采用微波消解作为样品前处理手段,原子荧光法和电感耦合等离子体质谱法作为检测方法,采用标准物质对两种方法进行验证。结果微波消解-原子荧光法检出限为0.006 mg/kg,线性相关系数为0.9998,相对标准偏差为6.3%和3.2%;微波消解-电感耦合等离子体质谱法检出限为0.003 mg/kg,线性相关系数为0.9999,相对标准偏差为2.4%和2.6%。2种方法对标准物质的测定结果均在标准值允许范围内。结论2种方法均操作简便快速,具有较低的检出限、较高的准确度和精密度,其中原子荧光法适合批量样品分析,电感耦合等离子体质谱法适用于总砷含量较高的样品。     

ICP-MS测试卷烟纸中6种重金属的含量

使用微波消解的方式消解样品,采用电感耦合等离子体质谱仪同时测定卷烟纸中的铬、镍、砷、镉、汞和铅6种重金属含量;采用内标校正基体效应;采用碰撞池(CCT)模式消除Ni的质谱干扰。该方法相对标准偏差均小于7%、回收率为89.9%~102.7%、检出限为0.005~0.010mg/kg;能快速、准确测定卷烟纸中重金属含量。     

微波消解-电感耦合等离子体光谱法测定 铝塑包装奶粉中铝的含量

目的建立一种微波消解-电感耦合等离子体光谱仪器测定铝塑包装奶粉中铝的含量的方法。方法样品经微波消解并赶酸,采用电感耦合等离子体光谱(inductively coupled plasma emission spectrometry,ICP-AES)检测方法上机,通过样品中铝的信号强度和浓度成正比,对34种铝塑包装奶粉中的铝含量进行测定。结果该方法检出限为0.72 mg/kg,线性相关系数为0.9998,加标回收率为95.4%~98.6%。检测的34种铝塑包装奶粉中铝的残留量较少,均在低于0.72~1.28 mg/kg之间。结论该方法简便、快速、准确、所需样品量少,为奶粉的质量安全提供了技术保证。     

微波消解-电感耦合等离子体原子发射光谱法测定海参中铝的残留量

目的建立微波消解-电感耦合等离子体原子发射光谱测定海参中铝含量的方法,并对北京市场中海参中铝含量进行初步调查。方法抽取市场上37个海参样品,经5 m L硝酸微波消解后,采用电感耦合等离子体原子发射光谱法进行测定。结果该方法检出限为5.0 mg/kg,加标回收率为95%~105%。通过单因素方差分析,本方法的测定结果与国标方法测定所得的数据结果无显著差异。测定的37个样本中均检出铝,其中最低含量为29.2 mg/kg,最高含量为304 mg/kg,100 mg/kg以上的样本占62.2%。结论本方法具有准确度高、精密度好、操作简单、分析速度较快等特点。从市场抽样检测结果来看,海参中铝安全应该引起一定的重视,建议生产企业进一步改进生产工艺,确保海参质量安全。     

半消解–电感耦合等离子体质谱法同时测定油菜籽中多元素的含量

采用半消解–电感耦合等离子体质谱法同时测定油菜籽中的钙、铁、铜、铅、锌、镉、锰、镁、总砷九种无机元素,对半消解的条件和电感耦合等离子体质谱法的条件进行了优化研究,对微波消解法与半消解样品前处理进行了比对,采用配对t检验进行验证。结果表明:与国标GB5009.268的微波消解法比较无显著性差异,该方法的相对标准偏差在2.5%~14.5%之间,九种元素的方法检出限在0.001~0.14 mg/kg之间。应用于油菜籽样品中九种金属元素的测定,结果令人满意。     

微波消解电感耦合等离子体质谱法测定大花红景天中有害重金属的方法

目的建立微波消解电感耦合等离子体质谱(ICP-MS)法同时测定大花红景天中有害重金属的方法。方法以硝酸+过氧化氢作为消解体系,微波消解用作前处理,电感耦合等离子体质谱作为检测手段,同时测定大花红景天中铅(Pb)、砷(As)、汞(Hg)、镉(Cd)、铜(Cu)的含量。结果 Pb、As、Hg、Cd、Cu线性关系良好(r≥0.9995),方法检出限0.005~0.01 mg/kg,方法回收率85.5%~97.1%,RSD 0.6%~6.1%。结论本法简便、准确、灵敏度高,重复性好,可为大花红景天的质量控制提供依据。     

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.     

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.     

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.     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

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.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.