微波消解-原子荧光法同时测定果品中的砷和汞

建立了微波消解-原子荧光法同时测定果品中砷和汞的方法.砷、汞检出限分别为0.1145 μg/L和0.0161μg/L,相关系数达到0.999 8.用该方法进行加标回收实验,砷的回收率为99.48%,汞的回收率为94.75%;测定标准物质砷和汞的含量,均在含量标准值许可范围,相对标准偏差分别为2.59%和4.06%,准确度和精密度高.     

微波消解-原子荧光光谱法测定莱芜香肠中的砷和汞

建立了一种测定莱芜香肠中砷和汞的微波消解-原子荧光光谱法,莱芜香肠样品微波消解后,采用标准曲线法进行测定。结果表明,砷与汞的线性范围分别为0.0~8.0μg/L及0.0~0.8μg/L;相关系数分别为0.99967和0.99977;砷的加标回收率为97.7%~101.0%,相对标准偏差(n=6)为0.88%,检出限为0.052μg/L;汞的加标回收率为96.4%~102.9%,相对标准偏差(n=6)为1.09%,检出限为0.003μg/L。结果显示该方法灵敏度高、简便快捷、可准确测定莱芜香肠中砷和汞的含量。     

苹果、脐橙中铅和汞的快速测定的方法研究

研究一种简单快速测定苹果和脐橙中铅和汞的方法。在铁氰化钾-酒石酸体系下,用微波消解-原子荧光光谱法快速测定铅和汞的含量。结果表明:在优化的工作条件下,铅和汞的线性范围分别为0~100μg/L和0~2.00μg/mL,检出限分别为0.37μg/L和4.64×10-3μg/L,加标回收率为98.5%和97.1%,相对标准偏差均小于5%(n=11)。该方法具有操作简便、快速、灵敏度高的优点,可作为苹果和脐橙中微量铅和汞快速测定的方法。     

微波消解-氢化物发生双道原子荧光光谱法同时测定糖蜜中的砷和汞

建立了微波消解-氢化物发生双道原子荧光光谱法同时测定糖蜜样品中砷和汞的分析方法。实验探索了酸的种类比例、固液比、微波强度、消解时间等各种微波消解条件,并对工作条件进行了优化。仪表检出限为砷0.0704μg/L,汞0.0089μg/L;精密度为砷1.13%,汞0.49%;样品加标回收率为砷96.1%～107.6%,汞102.3%～105.1%。应用该方法对广西某制糖集团下属公司的糖蜜中砷和汞的含量进行了分析,结果令人满意。     

微量酸微波消解-原子荧光光谱法同时测定食品中砷、汞

为建立同时测定食品中砷、汞微量酸微波消解-原子荧光光谱法,采用1ml硝酸 0.5ml过氧化氢 6ml水的微波消解体系,用0.5g抗坏血酸 1g硫脲为As5 预还原剂,消解液无需赶酸,直接用原子荧光光谱仪同时测定。砷在0～200ng/ml、汞在0～40ng/ml范围内线性关系良好,相关系数均大于0.9995。方法的检出限砷0.12ng/ml、汞0.04ng/ml。检测国家标准物质GBW08508米粉、GBW08513茶树叶,相对标准偏差砷3.94%,汞3.22%,平均回收率砷96.1%;汞93.6%。该方法试剂用量少,污染小,简便、快速、准确,能满足各类食品中砷、汞检测。     

原子荧光光谱法检测食用鱼中汞、砷含量

目的：建立原子荧光光谱法同时测定食用鱼中汞、砷含量的方法。方法：采用微波消解法对样品进行预处理,原子荧光光谱法同时测定食用鱼(淡水鱼、海水鱼)中汞、砷含量,分析其检测结果。结果：汞在0～10.0μg·mL^-1时线性关系良好,砷在0～40.0μg·mL^-1时线性关系良好,相关系数> 0.999。汞的检出限在2.50～3.83μg·m L^-1,回收率为94.1%～99.0%,精密度为2.9%;砷的检出限在2.30～3.68μg·mL^-1,回收率为93.3%～99.2%,精密度为2.0%。对比发现食用海水鱼中汞、砷含量显著高于淡水鱼(P <0.05)。结论：原子荧光光谱法操作简单、检测灵敏度较高,可同时测定食用鱼汞、砷含量。     

湿法消解-原子荧光光谱法同时检测海产品中的总砷与总汞

目的建立湿法消解-原子荧光光谱法同时测定海产品中总砷、总汞含量的分析方法。方法采取硝酸、高氯酸和硫酸混合体系的冷消解及热消解结合的方法,并采用电炉高温短时间加热的优化条件进行消解样品,利用氢化物原子荧光光谱法同时进行总砷、总汞的测定。结果砷在0～40μg/L浓度范围内呈良好线性关系,汞在0～12μg/L浓度范围内呈良好线性关系,相关系数均大于0.999。砷的检出限为0.037μg/L,回收率为94.36%～96.62%,精密度为0.86%～1.36%,汞的检出限为0.048μg/L,回收率为93.33%～95.28%,精密度为0.88%～2.62%。通过对能力验证HMRL1601海鱼粉中总汞、总砷的检测,检测结果总汞为0.30 mg/kg,总砷为2.06 mg/kg,均为满意结果,黄鱼、紫菜质控样的检测值均在参考值允许范围内。结论该方法操作简便、准确灵敏,适用于每一个实验室开展海产品中总砷总汞的同时测定。     

氢化物发生原子荧光光谱法同时测定进出口蜂皇浆中有害元素砷、汞

建立微波消解-氢化物发生原子荧光光谱法(HG-AFS)时测定进出口蜂皇浆中砷、汞残留的方法,并对HC-AFS工作参数及条件进行了优化和选择.As检出限为0.07μg/L,Hg检出限为0.008μg/L,回收率范围为94%～101%.操作简便、快速、灵敏度高,应用于进出口蜂皇浆中砷、汞残留的检测取得满意的结果.     

原子荧光光谱法测定皮革中砷和汞的条件优化

用硝酸、过氧化氢微波消解处理皮革样品,获得均匀的样品消解液。用原子荧光光谱法测定皮革中的砷和汞,并优化了测定条件。砷的相对标准偏差≤3．8％,方法检出限为0．0376μg/L,回收率为97．8％～102．8％;汞的相对标准偏差为≤7．2％,方法检出限为0．0046μg／L,回收率为95．0％-103．0％。     

原子荧光光谱法测定六种天然香辛料调味品中的砷、汞、硒

该研究利用原子荧光光谱法测定了6种天然香辛料调味品中砷、汞、硒的含量。在优化的实验条件下,3种元素的检出限介于0.02～0.03μg/L之间,符合测定要求。该方法测定砷的回收率为96.9%～106.3%,汞的回收率为97.8%～102.8%,硒的回收率为95.7%～103.5%,6种天然香辛料调味品中砷、汞、硒含量均未超出限量值。该方法准确、灵敏、快速,可应用于天然香辛料调味品样品中砷、汞、硒的同时测定。     

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.     

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.     

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.     

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.     

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.