分子印迹固相萃取-高效液相色谱法测定植物油中11种多环芳烃

建立了同时测定植物油中11种多环芳烃的分子印迹固相萃取-高效液相色谱荧光检测方法。样品使用环己烷溶解,经分子印迹固相萃取柱净化,得到的洗脱液氮吹后使用乙腈复溶,通过PAHs专用C_(18)色谱柱分离,采用高效液相色谱-荧光检测器定量检测。结果表明:本方法在0. 5～200 ng/mL线性关系良好,11种组分加标回收率在63.5%～118.6%,相对标准偏差1.4%～18.2%,最低检出限为0.03～1.50μg/kg,定量限为0. 10～5. 00μg/kg。本方法前处理简单、快速、灵敏度高,适合植物油中多环芳烃的快速准确测定。     

气相色谱-同位素稀释质谱法测定肉中多环芳烃含量

采用分子印迹固相萃取技术,建立肉中多环芳烃残留的气相色谱-同位素稀释质谱检测方法。以萘-D8为内标、正己烷-二氯甲烷（7∶3,V/V）混合溶液为提取试剂,经过匀浆、超声提取、离心、分子印迹固相萃取等步骤,在优化仪器条件下进行定性、定量分析。在5～100 ng/mL范围内,16 种多环芳烃峰面积与内标物峰面积的比值均与质量浓度的比值呈良好的线性关系,线性相关系数不小于0.999 9,肉及肉制品中检出限为0.125～0.625 μg/kg。3 个加标水平下的样品回收率在85.7%～109%之间,相对标准偏差（n=6）在0.75%～4.90%之间。该方法前处理效率高,定量法灵敏、准确,适合于监控肉类中多环芳烃的含量。     

全自动分子印迹固相萃取高效液相色谱法测定食用油中10种多环芳烃

为快速测定食用油中的多环芳烃,建立全自动分子印迹固相萃取高效液相色谱法测定食用油中10种多环芳烃的分析方法。将样品用正己烷溶解,以2 mL正己烷为淋洗液,二氯甲烷为洗脱剂,经全自动分子印迹固相萃取柱净化,氮吹后定容进高效液相色谱仪(配荧光检测器)检测。结果表明：所建方法线性关系良好,检出限为0.1～1.3μg/kg,定量限为0.3～4.0μg/kg;方法的准确度良好,精密度高,10种多环芳烃在玉米油和花生油基质中的加标回收率为79.2%～114.3%,相对标准偏差为0.4%～5.7%,将该方法应用于实际食用油样品中苯并[a]芘的测定,所测样品中苯并[a]芘含量均未超出国标限量。所建方法前处理简单快速,可实现固相萃取柱的自动化处理,减少有机溶剂的消耗,适合食用油中多环芳烃的快速测定。     

分子印迹固相萃取-气相色谱-串联质谱法测定油茶籽油中16种多环芳烃

为稳定可靠地分析油茶籽油中多环芳烃,建立了分子印迹固相萃取-气相色谱-串联质谱测定油茶籽油中16种多环芳烃方法。样品经正己烷溶解后,分别采用反相固相萃取HLB小柱、弗罗里硅土小柱和分子印迹固相萃取小柱对16种多环芳烃进行净化。以回收率和基质效应为考察指标评估3种固相萃取柱的净化,在此基础上,对净化液进行低温低速氮吹浓缩,多反应监测扫描模式下进行气相色谱-串联质谱检测,外标法定量。结果表明：分子印迹固相萃取小柱对16种多环芳烃的净化效果最佳;16种多环芳烃在质量浓度1～50 μg/L范围内线性关系良好（R2≥0.995 1）,检出限为0.01～ 0.20 μg/kg,在2、10 μg/kg和20 μg/kg加标水平下的回收率为71.5%～116.3%,相对标准偏差为1.5%~13.8%。该方法具有灵敏度高、检出限低、重复性好等特点,适用于油茶籽油中16种多环烃的测定。     

固相萃取-高效液相色谱法检测植物油中15种多环芳烃

建立了固相萃取-高效液相色谱荧光法检测植物油中15种多环芳烃(PAHs)的新方法.植物油样品经正己烷稀释后,非芝麻油样品采用多环芳烃专用柱净化,芝麻油样品采用硅胶柱串接多环芳烃专用柱净化,ZORBAX Eclipse PAH色谱柱(4.6 mm×250 mm,5μm)分离,以水-乙腈作为流动相,梯度洗脱,外标法定量.1...     

全自动固相萃取净化-高效液相色谱法测定食用植物油中苯并(a)芘含量

为提高工作效率,降低误差,建立分子印迹柱全自动固相萃取净化-高效液相色谱法测定食用植物油中苯并(a)芘含量的方法。样品经正己烷提取,采用全自动固相萃取仪进行分子印迹柱净化,C18色谱柱分离,高效液相色谱-荧光检测器检测。结果表明：苯并(a)芘在0.5～20.0 ng/mL质量浓度范围内与峰面积线性关系良好,相关系数为0.999 9,方法检出限为0.09μg/kg,定量限为0.30μg/kg,加标回收率为91.7%～111.8%,相对标准偏差为2.0%～8.2%,与国标方法的检测结果不存在显著性差异;对市售38份食用植物油样品进行检测发现,苯并(a)芘的检出率为76.3%。该方法准确度高、重复性好,可批量自动化前处理样品,提高工作效率,并降低人员操作误差风险,适用于食用植物油中苯并(a)芘含量的测定。     

分子印迹固相萃取–高效液相色谱法的优化及在测定植物油中苯并(a)芘含量的应用

建立优化的分子印迹固相萃取超高效液相色谱法测定植物油中苯并芘的检测方法。实验过程中通过对样品不同固相萃取净化效能、最佳检测波长、流动相体系及色谱柱使用的考察,结果表明,分子印迹固相萃取净化柱比较适合植物油样品的前处理萃取及净化,最佳检测波长为激发波长365 nm和发射波长410 nm,苯并芘色谱峰在此条件下具有较高的响应值和信噪比,在90%乙腈–10%水流动相体系下,目标峰具有较好的分离效果,采用150 mm的短柱子能有效提高工作效率。苯并芘在浓度0.3~20 μg/L范围内具有良好的线性关系,相关系数大于0.999 9,方法检出限为0.05 μg/kg,定量限为0.10 μg/kg,3个添加浓度水平的平均回收率为87.6%~95.9%,相对标准偏差为1.08%~2.16%。实际样品检测中,苯并芘的检出率为39.0%,超标率为2.4%,合格率为97.6%。该优化方法灵敏度高,操作便捷,快速准确,可适用于植物油中苯并芘的批量检测及污染监测情况分析。     

高效液相色谱法同时测定麻花中16种多环芳烃含量

目的 建立高效液相色谱法测定麻花中16种多环芳烃（PAHs）含量的分析方法。方法 样品经正己烷提取,提取液经弗洛里硅藻土固相萃取小柱柱串联PAHs专用固相萃取小柱净化,Waters PAH C18柱分离,采用高效液相色谱法测定,外标法定量。结果 苊烯在5~200 ng/mL范围内呈现良好的线性关系,相关系数（r）为0.9996,其他15种多环芳烃在1~200 ng/mL范围内呈现良好的线性关系,相关系数（r）为0.9985~0.9998;方法的检出限为0.4~2.5 μg/kg;在5、10、25 μg/kg 3个添加水平的平均回收率为63%~95%, 相对标准偏差小于10%。结论 该方法净化效果好,具有较好的准确度、灵敏度和精密度,可用于麻花中多环芳烃的测定。     

高效液相色谱法同时测定植物油中的15种多环芳烃

建立高效液相色谱-荧光法测定植物油中的15种多环芳烃。方法 样品用正己烷溶解,过中性氧化铝固相萃取小柱净化,采用Waters-PAHs专用柱(4.6mm×250mm,5μm)分离,乙腈-水梯度洗脱,流速1.5ml/min,柱温30℃,进样量10μl;荧光检测器检测,外标法定量。结果 方法检出限在0.15～2.0μg/kg之间,样品加标回收率在78.0%～115.2%之间,RSD在0.2%～2.0%之间。结论 该方法具有前处理简单、灵敏度高、重复性好等优点,可用于植物油中15种多环芳烃的含量测定。     

分子印迹固相萃取-高效液相色谱法测定酱油中酪胺含量

目的建立分子印迹固相萃取与高效液相色谱联用快速测定酱油中酪胺含量的方法。方法采用本体聚合法以酪胺为模板分子,对乙烯基苯甲酸(P-VBA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,制备分子印迹聚合物为填料自制固相萃取柱。对上样溶剂、流速、淋洗及洗脱溶剂等条件进行优化,采用优化的条件萃取酱油中的酪胺,高效液相色谱测定。结果固相萃取优化条件为:上样溶剂为5%乙醇水溶液,10%甲醇为淋洗液,40%乙腈为洗脱液,流速均控制在0.5 mL/min。在加标浓度为5μg/mL和10μg/mL的3种酱油所得到的平均回收率在86.95%~106.06%之间。结论本方法能快速分离酱油中酪胺,样品前处理效率高,方法灵敏度高,适用于食品中酪胺的痕量分析。     

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.