HPLC-柱后光化学衍生法检测花生酱中黄曲霉毒素

建立高效液相色谱-在线柱后光化学衍生-荧光检测器检测花生酱中黄曲霉毒素B1、B2、G1、G2的含量。样品以乙腈-水(80∶20)溶液提取,经免疫亲和柱净化后,利用在线柱后光化学衍生-HPLC-FLD进行分析测定。结果:在优化条件下,黄曲霉毒素B1、G1在0.30 mg/L~10 mg/L,黄曲霉毒素B2、G2在0.06 mg/L~3.0mg/L线性关系良好,r0.998,回收率80%~101%,RSD5.9%。黄曲霉毒素B1、B2、G1、G2的检测限(LOD)分别为0.10、0.03、0.15、0.04μg/kg。     

IAC-HPLC法检测牛奶中黄曲霉毒素和玉米赤霉醇及类似物质量分数

建立了IAC-HPLC(免疫亲和柱净化-高效液相色谱)法检测牛奶中6种黄曲霉毒素和玉米赤霉醇及类似物的方法。样品经免疫亲和柱净化后,黄曲霉毒素用高效液相色谱——荧光检测器柱后衍生检测,玉米赤霉醇及其类似物用高效液相色谱——紫外检测器检测。结果表明,牛奶中黄曲霉毒素(M2,M1,G2,G1,B2,B1)的检测限分别为0.004,0.004,0.004,0.003,0.002,0.002μg/L,6种黄曲霉毒素的平均回收率在91.20%~113.8%之间,变异系数小于8.79%;玉米赤霉醇及其类似物的检测限均为0.05μg/L,平均回收率在54.22%~90.76%之间,变异系数小于9.44%。     

免疫亲和柱净化-光化学柱后衍生高效液相色谱 荧光法测定粮食中黄曲霉毒素

建立了粮食中黄曲霉毒素B1、B2、G1、G2的免疫亲和柱净化-光化学柱后衍生高效液相色谱荧光检测法。样品经甲醇-水提取,免疫亲和柱净化,高效液相色谱分离,光化学柱后衍生,荧光检测器测定。结果表明,黄曲霉毒素B1、B2、G1、G2的检出限分别为0.50、0.25、0.50、0.25μg/kg,回收率为67.2%～91.7%,RSD小于10%。该方法快速、准确、灵敏度高、重现性好,能满足我国对粮食中黄曲霉毒素限量的检测要求。     

液相色谱法自制净化柱测定饲料中5种黄曲霉毒素

通过用自制净化柱净化,利用高效液相色谱仪对饲料中的黄曲霉毒素B1、B2、G1、G2、M1同时进行检测,样品经体积分数为84%的乙腈溶液提取,提取液通过自制净化柱净化、浓缩,三氟乙酸(TFA)柱前衍生,C18色谱柱分离,荧光检测器检测,外标法定量。5种黄曲霉毒素经过衍生后线性良好,对添加黄曲霉饲料样品进行加标回收,回收率在85%~102%,效果良好。     

玉米制品中黄曲霉毒素的柱前和柱后衍生方法对比

玉米制品中黄曲霉毒素测定的2种衍生化方法(柱前衍生和柱后衍生)进行比较。样品经过Mycrosep ~(TM)226多功能净化柱净化,采用Waters Symmetry C18(4.6 mm×250 mm,5.0μm)色谱柱进行分离,荧光检测器检测。柱前衍生法:样品提取液经净化后,采用三氟乙酸进行衍生后测定。柱后碘衍生法:样品提取液经净化后,经高效液相色谱分离、柱后碘衍生,荧光检测器检测。结果表明:柱前衍生法,黄曲霉毒素G_1、B_1检出限为0.05μg/kg,黄曲霉毒素G_2、B_2检出限为0.015μg/kg,r0.999 1,回收率在75.4%~84.2%之间;柱后碘衍生法,黄曲霉毒素G_1、B_1检出限为0.08μg/kg,黄曲霉毒素G_2、B_2检出限为0.015μg/kg,r0.999 2,回收率在75.2%~85.7%之间。2种衍生方法在线性范围、精密度、回收率等方面较相似,表明柱前衍生法和柱后碘衍生法均适用于玉米制品中的黄曲霉毒素检测。     

无需衍生化样品处理快速测定食品中 黄曲霉毒素B1

建立无衍生-超高效液相色谱法测定食品中的黄曲霉毒素B1的快速检测方法。样品经甲醇-水提取,免疫亲和柱净化,C18色谱柱分离、大体积流通池荧光检测器检测。黄曲霉毒素B1在0.10 ng/ml~5.00 ng/ml范围内与峰面积呈良好线性关系,R2>0.999,在6种基质,0.50 μg/kg~2.00 μg/kg范围内加标,平均回收率在71.7%~111.2%之间,相对标准偏差(RSD)为3.8%~11.5%,检出限(LOD)为0.05 μg/kg。本方法灵敏、快速、无衍生、结果准确,能够满足食品中黄曲霉毒素B1残留的检测需求。     

无需衍生化样品处理快速测定食品中黄曲霉毒素B_1

目的建立无需衍生化法.超高效液相色谱直接测定食品中的黄曲霉毒素B_1的快速检测方法。方法样品经甲醇.水(7:3,v:v)提取,免疫亲和柱净化,C_(18)色谱柱分离后,采用大体积流通池荧光检测器检测。结果黄曲霉毒素B_1在0.10~5.00 ng/mL范围内与峰面积呈良好线性关系,R~20.999,在饼干、粉丝、点心、沙琪玛、蛋糕、辣椒酱6种基质中,黄曲霉毒素B_1在0.50~2.00μg/kg范围内加标,平均回收率在71.7%~111.2%之间,相对标准偏差(RSDs)为3.8%~11.5%,检出限(LOD)为0.05 gg/kg。结论本方法灵敏、快速、无衍生、结果准确,能够满足食品中黄曲霉毒素B_1残留的检测需求。     

免疫亲和柱净化-在线柱后光化学衍生-高效液相色谱-荧光检测法快速测定食品中的黄曲霉毒素含量

目的 通过建立免疫亲和柱净化-在线柱后光化学衍生-高效液相色谱-荧光检测法探索快速测定食品中的黄曲霉毒素含量的方法。方法 样品经甲醇-水(V/V, 7︰3)提取, 免疫亲和柱净化、富集、淋洗后, 收集洗脱液, 洗脱液经Acclaim?120 C18 柱分离, 在254 nm紫外光下进行光化学衍生, 用荧光检测器进行测定。结果 黄曲霉毒素G2, G1, B2, B1检测限均小于2 μg/kg, 加标回收率为94.3%~108.8%。 结论 该方法能连续操作, 节省人力, 可用于食品中黄曲霉毒素含量的测定。     

免疫亲和层析净化-高效液相色谱法同时测定牛奶和奶粉中黄曲霉毒素B1、B2、G1、G2、M1、M2

建立牛奶和奶粉中黄曲霉毒素B1、B2、G1、G2、M1、M2的免疫亲和层析净化和柱后衍生高效液相色谱测定方法。样品经溶解、离心、过滤后,通过免疫亲和柱,黄曲霉毒素特异性抗体选择性地与存在的黄曲霉毒素抗原键合,形成抗体-抗原复合体。甲醇-乙腈混合溶液(4:5,v:v)洗脱,带荧光检测器的高效液相色谱仪经柱后衍生测定,外标法定量。标准曲线线性良好,添加回收率在57.0%～88.7%,相对标准偏差在3.37%～16.9%,牛奶中各黄曲霉毒素检出限:B1为2ng/kg,B2为1ng/kg,G1、G2为3ng/kg,M1、M2为5ng/kg;奶粉中B1为20ng/kg,B2为10ng/kg,G1、G2为30ng/kg,M1、M2为50ng/kg,检测低限能够满足各国对牛奶和奶粉中黄曲霉毒素的限量要求。该方法准确、快速、灵敏度高,适用于牛奶和奶粉中黄曲霉毒素的测定。     

HPLC-FLD柱前衍生法同时测定烟草中黄曲霉毒素B_1、B_2、G_1和G_2

通过溶剂萃取、免疫亲和柱纯化富集、三氟乙酸柱前衍生、高效液相色谱(HPLC)法分离及荧光检测器检测,建立了同时测定烟草及烟草制品中黄曲霉毒素B1、B2、G1和G2的免疫亲和检测方法。结果表明:1该方法可在20 min内完成测定,4种目标物能够得到很好的分离,线性关系良好,相关系数r值均大于0.99。2方法的回收率为85%~117%,相对标准偏差为0.2%~9.4%(n=6),其中B1的检出限和定量限分别为0.10和0.34μg/kg。     

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.     

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.     

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.     

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.