固相萃取-气相色谱-串联质谱法测定木耳中五氯苯酚

目的 研究建立木耳中五氯苯酚的固相萃取-气相色谱串联三重四极杆质谱（Gas chromatography-tandem triple quadrupole mass spectrometry,GC-MS/MS）测定方法。方法 以2,4,6-三溴苯酚为内标物,样品经5%三氯乙酸（Trichloroacetic acid,TCA）浸提,以乙酸乙酯/正己烷液-液分配法萃取五氯苯酚,经SLC（氧化铝/SCX）固相萃取柱净化样品提取液,乙酸酐衍生,HP-5MS 30m×0.25mm×0.25μm毛细管柱分离样品,GC-MS/MS多反应监测（Multiple Reaction Monitoring, MRM）测定,内标法定量。结果 建立的五氯苯酚方法浓度在1~100 ng/mL范围具有良好线性关系,线性相关系数（γ）:>0.9999,在方法线性范围内低、中、高三个浓度水平加标回收率在89.3%~108.7%之间,相对标准偏差2.1%~9.0%。方法检出限为0.06μg/kg,定量限为0.2μg/kg。结论 建立的五氯苯酚测定方法灵敏度高,方法稳定,重现性好,可用于木耳样品中五氯苯酚的定性定量测定。     

气相色谱-负化学源质谱法测定河蟹中五氯苯酚 及其钠盐的残留量

目的测定河蟹可食部分中五氯苯酚及其钠盐的残留量。方法样品在酸性介质中经正己烷提取、HLB固相萃取柱净化后,用甲醇洗脱,吹干后用碳酸钾溶液溶解,经衍生化反应生成的衍生物由正己烷提取,采用选择离子监测模式进行质谱测定。选择~(13)C_6-PCP作为内标物,通过对离子源及其温度、定性离子和定量离子的选择,建立气相色谱-负化学源质谱法测定河蟹可食部分中五氯苯酚及其钠盐残留量的检测方法。结果五氯苯酚乙酸酯在0.2~20.0μg/L范围内的线性关系良好,相关系数r=0.999,五氯苯酚在添加水平为5.0、10.0和50.0μg/kg时的平均回收率在87.2%~96.9%之间,测定相对标准偏差(n=6)在2.8%~6.3%之间,方法检测限为1.0μg/kg。结论该方法的检测准确度和精密度良好,能够用于河蟹样品中五氯苯酚及其钠盐残留的定性与定量测定。     

涡旋振荡提取-LC-MS/MS法测定皮革制品中的五氯苯酚残留量

采用涡旋振荡提取技术,以氢氧化钠溶液为萃取剂,建立了一种环保、低毒、快速测定皮革及其制品中五氯苯酚残留量的液相色谱-串联质谱(LC-MS/MS)法。对方法中影响五氯苯酚测定的各因素进行了优化。在优化条件下,当五氯苯酚质量浓度在0.25～80.00μg/L,与其对应的峰面积呈良好线性关系,相关系数(R~2)为0.999 9;定量下限为6.25μg/kg,检出限为2.50μg/kg,适合痕量及微量五氯苯酚的分析;不同水平加标回收率分别为86.5%、94.3%、95.2%,相对标准偏差(RSDs)分别为5.6%、4.9%、4.5%,具有较低的检出限和较好的回收率。     

高效液相色谱-串联质谱法测定食品用纸制品中氯酚类化合物残留量

目的建立高效液相色谱-串联质谱(HPLC-MS/MS)同时测定食品用纸制品中2,4-二氯酚、2,4,6-三氯酚、2,3,4,6-四氯酚、五氯酚4种氯酚类化合物残留量的检测方法。方法样品经0.5%甲酸甲醇超声提取后,混合型阴离子交换固相萃取柱净化,以HSS T3色谱柱(2.1 mm×100 mm,1.8μm)分离待测物,采用电喷雾离子化,负离子扫描和多反应监测模式(MRM)检测,以保留时间和特征离子对定性,内标法定量。结果 4种待测物在5～100μg/L浓度范围内线性关系良好,相关系数(r)均大于0.99;方法检出限为0.01～0.02 mg/kg,定量限为0.03～0.06 mg/kg;4种物质的添加水平为0.03～0.14 mg/kg时,平均回收率为80.1%～110.4%,相对标准偏差为3.2%～9.9%(n=6)。结论该方法样品前处理简单,准确性、精密度和灵敏度均较好,适用于食品用纸制品中4种氯酚类化合物残留量的检测。     

优化气相色谱-质谱法测定水果和蔬菜中五氯硝基苯残留量的前处理方法

目的建立检测水果和蔬菜中五氯硝基苯残留量的气相色谱-质谱联用方法。方法样品采用3种不同前处理法进行提取净化后,采用内标法进行定量。优化样品预处理方法,选择适宜的提取溶剂、最佳的超声和振荡时间,采用选择性离子扫描模式进行质谱检测。结论在0.02~0.10μg/m L添加水平,经正己烷提取和Qu ECh ERS柱净化处理的样品,其五氯硝基苯的平均回收率在68.32%~96.82%之间,相对标准偏差为3.4%~5.9%(n=6)。以信噪比S/N=3计算五氯硝基苯的最低检出限为0.002 mg/kg,方法的定量限为0.0067 mg/kg(S/N=10)。结论优化后的前处理方法结果准确、重现性好,检出限相对较低,满足水果和蔬菜中五氯硝基苯残留量的检测要求。     

全自动固相萃取气相色谱-质谱法同时测定苹果中五氯硝基苯和百菌清残留量

目的:建立全自动固相萃取气相色谱-质谱联用(Auto-SPE GC-MS)同时测定苹果中五氯硝基苯和百菌清残留量的分析方法。方法:样品经乙腈提取,全自动固相萃取仪净化后,采用内标法进行检测。结果:在(0.10~2.00)μg/m L添加水平,五氯硝基苯的平均回收率在83.6%~96.5%,相对标准偏差为5.5%~7.1%(n=10);百菌清的平均回收率在87.0%~97.2%,相对标准偏差为5.6%~10.0%(n=10)。以信噪比RSN=3计算2种农药残留的最低检出限,五氯硝基苯的最低检出限为0.003 mg/kg,百菌清的最低检出限为0.001 mg/kg。结论:该方法自动化程度高,结果准确度和重现性好,检出限较低,可满足苹果中五氯硝基苯和百菌清残留量的同时检测要求。     

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。     

液相色谱-质谱/质谱法快速测定牛奶中的氯舒隆残留量

建立快速测定牛奶中氯舒隆残留量的液相色谱-质谱/质谱(LC-MS/MS)检测方法。样品用乙腈提取,Quechers方法净化后,采用LC-MS/MS电喷雾负离子(ESI-)电离,多反应监测(MRM)模式检测,外标法定量。方法定量限为5μg/kg。在添加水平为5～100μg/kg的范围内,氯舒隆的回收率为92.8%～99.3%;相对标准偏差(RSD)不高于4.7%。     

DSPE-LC-MS/MS法测定海红果中9种杀菌剂残留量

建立分散固相萃取(DSPE)-液相色谱-质谱法(LC-MS/MS)测定海红果中9种杀菌剂(嘧霉胺、百菌清、稻丰散、甲霜灵、三唑酮、五氯硝基苯、烯酰吗啉、咪鲜胺、苯醚甲环唑)残留量的检测方法。样品匀浆粉碎后经乙腈提取、氧化铝萃取剂净化后,采用Atlantis T3色谱柱分离,LC-MS/MS测定。结果表明:9种杀菌剂在5.0μg/L~500μg/L范围内,呈良好的线性关系,线性相关系数R~2≥0.999 3;检出限为0.03μg/kg~1.0μg/kg,定量限为0.1μg/kg~3.0μg/kg;回收率在80.4%~102.3%,相对标准偏差(RSD)在1.1%~5.8%之间。     

鳗鱼中三氯杀螨醇残留量的GC／MS分析

建立了鳗鱼中三氯杀螨醇残留量的GC/MS分析方法.样品经正己烷提取、浓硫酸净化后,利用气相色谱.质谱进行分析.在25～200μg/kg添加水平,回收率在72.9%/～82.9%之间,变异系数在5.7%～8.0%之间.以S/N=3计算,方法检出低限为5μg/kg.结果表明,该法简便、灵敏、准确,适用于鳗鱼中三氯杀螨醇残留量的分析.     

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.