微波萃取/GC-MS测定纸质食品包装材料中双酚A

以丙酮为萃取剂,建立了微波萃取/气相色谱-质谱法(GC-M S)测定纸质食品包装材料中双酚A含量的分析方法。考察了微波萃取温度与时间对萃取效果的影响,选择了最佳的微波萃取条件。结果表明:方法的检出限为0.05m g/kg,样品的加标回收率为84.2%~95.4%,相对标准偏差小于4.6%。该方法具有快速、方便、灵敏度高等优点,适合于纸质食品包装材料中双酚A含量的快速测定。     

纸质食品包装材料中五氯酚的测定

以2,3,6-三氯酚为内标物,采用气相色谱-电子捕获检测器(GC-ECD)法对纸质食品包装材料中五氯酚的含量进行测定,并对五氯酚萃取条件进行优化。该方法简便准确、灵敏度高,在信噪比为3时,检出限为0.02mg/kg,平均回收率为99.5%～100.4%,相对标准偏差为2.0%～4.9%。结果表明,所检测的市售各种纸质食品包装材料中五氯酚的残留量均较低。     

食品塑料包装材料中有机锡化合物分析方法研究进展

有机锡化合物具有脂溶性,易通过食品包装材料进入食物中产生富集,对人体具有一定毒性,其有机锡种类繁多、分析过程复杂,毒性问题日益受到人们广泛关注。对食品包装材料中有机锡化合物分析方法的研究进展进行了概述,对样品前处理方法进行了介绍:主要有超声波萃取、微波萃取、固相萃取和固相微萃取等。分析方法主要包括气相色谱法、气相色谱-质谱联用法、液相色谱-电感耦合等离子体原子发射光谱法及液相色谱-电感耦合等离子体质谱法等。最后,展望了食品包装材料中有机锡化合物分析方法的发展趋向。     

微波辅助萃取-GC-MS法测定鞋材中苯乙酮

建立了微波辅助萃取-气相色谱-质谱法(GC-MS)测定鞋材中苯乙酮含量的分析方法。考察了6种不同萃取溶剂对苯乙酮的萃取效率,最终选择丙酮为萃取溶剂,并研究了微波辅助萃取温度与时间对萃取效果的影响,选择了最佳的微波辅助萃取条件,萃取液经过净化和浓缩后,用气相色谱-质谱仪进行选择离子监测模式下的定性及定量分析。结果表明,苯乙酮在0.2~40 mg/L范围内呈线性关系,方法检出限为0.4 mg/kg,样品的加标回收率为92.4%~97.2%,相对标准偏差小于5.2%。该方法具有快速、方便、灵敏度高、定性准确等优点,适用于鞋材中苯乙酮含量的快速测定。     

皮革制品中富马酸二甲酯的快速检测

利用富马酸二甲酯在热水中快速溶解的性质,采用去离子水在一定温度下超声萃取,建立了测试皮革制品中富马酸二甲酯含量的萃取及气相色谱-质谱(GC-MS)检测方法。萃取过程中以水为萃取剂,超声波辅助萃取,然后用二氯甲烷进行反萃。在试验选定的最佳条件下,加标回收率为91.3%～95.8%,相对标准偏差小于5.6%。该方法具有快速、准确、灵敏度高等优点,适合于皮革制品中富马酸二甲酯含量的测定。     

微波萃取-气相色谱法测定纸质包装材料中五氯苯酚

建立了微波萃取-气相色谱法(GC-ECD)测定纸质包装材料中五氯苯酚含量的方法。以正己烷-丙酮混合物为萃取溶剂,考察了微波萃取温度与时间对萃取效果的影响,选择了最佳的微波萃取条件。萃取液经浓缩、净化、乙酸酐衍生后以气相色谱法测定。结果表明:该方法的检出限为0.025mg/kg,样品的加标回收率在86.4%～98.8%之间,相对标准偏差小于4.8%。该方法具有快速、方便、灵敏度高等优点,适用于纸质包装材料中中五氯苯酚含量的快速测定。     

纸质食品包装材料中禁用芳香胺迁移量的测定

用去离子水浸泡纸质食品包装材料,提取其中的禁用芳香胺,浸泡液过固相萃取小柱后,用甲醇淋洗,淋洗液经浓缩后用甲醇定容,进行气相色谱/串联质谱法测定.采用的测定模式为三重四级杆质谱电子轰击多反应监测模式,从而建立了一个同时测定纸质食品包装材料中禁用芳香胺迁移量的气相色谱/串联质谱方法,该方法的加标回收率为63.1％ ～98.4％,精密度(RSD)为2 6％～16.2％,在S/N(信噪比)=10的条件下,所有24种禁用芳香胺的检出限均小于1.0 ng/mL.     

微波萃取在检测纺织品中五氯苯酚上的应用

研究纺织品中五氯苯酚的检测方法。对微波萃取中的萃取溶剂、微波程序和衍生方式进行了优选。在微波环境下以正己烷-丙酮混合溶液为溶剂萃取纺织品中的五氯苯酚,然后采用乙酰化衍生方式处理提取液,最后使用气相色谱-质谱联用分析仪法对五氯苯酚的含量进行测定,并将微波萃取法与其他萃取方法所得结果进行了对比。试验表明:微波萃取-气相色谱-质谱联用检测法的检出限为0.05 mg/kg,线性范围为0.05 mg/L~2 mg/L,相关系数为0.999 93,加标回收率为93.4%~98.3%,相对标准偏差小于4.2%;与其他萃取方法相比,微波萃取法具有快速准确、灵敏度高等优势。认为微波萃取-气相色谱-质谱联用检测法是检测纺织品中五氯苯酚含量的高效方法。     

气相色谱-质谱法快速测定方便面中富马酸二甲酯

对方便面中富马酸二甲酯(DMF)的含量进行了分析研究,建立了测试方便面中富马酸二甲酯含量的气相色谱-质谱(GC-MS)分析方法。以乙酸乙酯为萃取溶剂,采用超声波萃取方式,并考察超声波萃取的温度和萃取时间。在试验选定的最佳条件下,采用选择离子监测(SIM)模式,气相色谱-质谱法对富马酸二甲酯进行定性和定量分析。该方法具有操作简便、快速、准确、灵敏度高等优点,适合于方便面中富马酸二甲酯含量的测定。     

气相色谱-质谱法测定塑料食品包装材料中4种有机锡

建立了气相色谱-质谱法测定塑料食品包装材料中4种有机锡(二甲基锡、三甲基锡、二乙基锡和一丁基锡)的分析方法。塑料食品包装材料样品经四氢呋喃溶解,甲醇沉淀杂质大分子后高速离心过滤,有机锡与四乙基硼酸钠反应生成有机锡的乙基衍生物,经正己烷萃取后,采用气相色谱-质谱法进行定性定量分析。在试验选定的最佳条件下,4种有机锡的线性范围在0.10~10mg/L之间,相关系数均大于为0.999,方法检出限为0.2~0.3 mg/kg之间,样品加标回收率为56.5%~109.4%,相对标准偏差小于12.6%。     

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.     

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.     

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.     

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.