固相萃取-气相色谱-串联质谱法同时测定红茶中113种农药残留

目的建立一种固相萃取净化(solid phase extraction, SPE)-气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry, GC-MS/MS)测定红茶中113种农药多残留的分析方法。方法样品采用1%(V:V)醋酸乙腈水溶液(2:1,V:V),加入6 g MgS04, 1.5 g乙酸钠进行提取。考虑到农药化合物结构的差异性影响,本文采用2种不同的净化方法,方法I是采用Cleanert TPT柱对95种农药进行净化,方法II采用PSA柱与50 mg石墨化碳黑(graphitized carbon black, GCB)对18种平面或类平面结构的农药进行净化,然后用GC-MS/MS进行分析,基质匹配标准溶液内标法定量。结果结果表明,113种农药在5～200 ng/mL范围内线性关系良好,相关系数均大于0.993,方法的添加回收率为50%～134.2%,相对标准偏差(relative standard deviations, RSD)为0.1%～13.7%,定量限(limits of the quantitation, LOQ)为10～50μg/kg。结论该方法灵敏度、准确度和精密度均能满足红茶中农药多残留的分析要求。     

气相色谱—串联质谱法同时测定黑茶中9种农药残留

建立了同时对黑茶中9种农药残留进行定性定量分析的气相色谱三重四级杆质谱确证方法。样品经乙腈提取、Cleanert TPT固相萃取柱净化后,用气相色谱—串联质谱MRM采集方式进行分析测定。研究结果显示:这9种农药在0.4～3.2mg/L浓度范围内与峰面积呈良好的线性关系,9种农药的相关系数均在0.99以上,相对标准偏差(RSD)为1.5%～5.6%,最低检出限均在1.0μg/kg以下,平均加标回收率为81.6%～98.6%。该方法分离效果好、准确度高、重现性好且操作简单快速。     

分散固相萃取-气相色谱串联质谱法同时测定食用植物油中的8种农药

食用植物油经乙腈提取后,经改进的分散固相萃取(QuEChERS)净化,采用气相色谱串联质谱(GC-MS/MS),在选择反应监测离子(SRM)模式下,进行质谱定性,外标法定量,建立了食用植物油中8种禁用农药残留的快速定量分析方法。结果表明,8种农药的回归方程相关系数均大于0.99,定量限为10μg/kg,平均回收率为81.3%~100.7%,相对标准偏差小于等于10.2%。     

QuEChERS-气相色谱-串联质谱法测定蔬菜水果中48种农药及其代谢物残留量

目的 建立了分散固相萃取(QuEChERS)法提取净化气相色谱串联质谱(GC-MS/MS)检测蔬菜水果中48种农药残留的方法。方法 试样经乙腈提取、氯化钠盐析、无水硫酸镁脱水、柠檬酸钠和柠檬酸二钠作为缓冲保护剂、陶瓷均质子利于萃取过程的均匀性,净化剂(900mg硫酸镁及150mgPSA)涡旋净化后离心,上清液滤膜过滤后GC-MS/MS测定。优化了提取溶剂、分散固相萃取条件、气相色谱条件及质谱条件。结果 本方法采用基质匹配线性-内标法定量,方法的加标回收率在65.5%-114.2%之间,精密度在2.2%-24.0%之间,线性范围为5～500μg/kg(R_²＞0.99),定量限为0.6μg/kg-1.3μg/kg。结论 该方法快速、准确、灵敏, 适合测定蔬菜水果中48种农药及代谢物残留量。     

基于QuEChERS-GC-MS/MS法同时测定猕猴桃中15种有机磷农药残留

建立改良的QuEChERS方法结合气相色谱-三重四极杆串联质谱（GC-MS/MS）法同时检测猕猴桃中15种有机磷农药残留的分析方法。样品前处理采用改进的QuEChERS方法,乙腈-乙酸乙酯（1∶1,V/V）作为提取溶剂,经100 mg乙二胺-N-丙基硅烷（PSA）、200 mg十八烷基硅烷键合硅胶（C18）、40 mg石墨化碳黑（GCB）、300 mg无水硫酸镁固相分散净化,用GC-MS/MS法在多反应监测（MRM）模式下分析检测,内标法定量。结果表明,15种有机磷农药在质量浓度0.05～1.00 μg/mL范围内线性关系良好,相关系数R2均＞0.998,方法检出限为0.001 2～0.326 5 μg/kg,定量限为0.004～1.088 μg/kg;其平均加标回收率为76.95%～101.2%,精密度试验结果的相对标准偏差（RSD）（n=6）为0.21%～10.05%。该方法具有净化效果好、重复性强、灵敏度高等优势,适用于猕猴桃样品中多种农药残留的同时检测。     

PRiME HLB固相萃取柱结合气相色谱-串联质谱法快速测定茶叶中200种农药残留

目的 建立PRiME HLB固相萃取柱结合气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)快速测定茶叶中200种农药残留量的分析方法.方法 样品用乙腈提取,经PRiME HLB通过式固相萃取柱净化,残留量采用气相色谱-串联质谱法进行检测.结...     

LC-MS/MS测定牛奶中氟虫腈及代谢物残留量

建立了液相色谱-串联质谱(LC-MS/MS)法测定牛奶中氟虫腈及其代谢物残留量的方法。根据基质及目标物特点选择乙腈进行提取,通过比较Cleanert PEP Plus固相萃取柱,Florisil固相萃取柱、Waters Oasis PRiME HLB净化柱,氨基石墨复合柱净化效果及实验效率,选择Cleanert PEP Plus(60 mg/3 mL)固相萃取柱净化。经C18色谱柱分离,以0.1%甲酸乙腈溶液和0.1%甲酸水溶液(含浓度10 mmol/L乙酸铵)为流动相进行梯度洗脱,选择负离子多反应监测模式检测,外标法定量。结果表明1~50μg/kg范围内线性关系良好,相关系数R²>0.99。方法的检出限为0.6μg/kg,定量限为1μg/kg。在空白牛奶基质中3个不同添加水平实验中回收率为82.5%~97.4%,相对标准偏差为4.0%~10.5%。该方法简便、快速、准确、灵敏,适用于牛奶中氟虫腈及残留物的测定。     

气相色谱-串联质谱法同时分析葡萄基质中 196种农药残留

目的建立同时分析葡萄基质中196种农药残留的气相色谱-串联质谱(GC-MS/MS)方法。方法葡萄样品经乙腈提取,QuEChERS方法净化,加入内标环氧七氯,采用GC-MS/MS在多反应监测模式(MRM)下分析,38 min内即可完成196种农药的分离,内标法定量。结果 196种农药在10~1000μg/L的浓度范围内线性关系良好,相关系数(r~2)大于0.99,各农药的检出限(S/N=3)为0.1~2.5μg/kg,各农药的定量限(S/N=10)为0.3~8.3μg/kg,在10.0μg/kg和50.0μg/kg 2个水平的添加浓度下,回收率在60.5%~126.2%之间,相对标准偏差0.2%~16.1%(n=6)。结论该方法准确可靠,灵敏度高,可用于葡萄基质中196种农药残留的同时检测。     

气相色谱-串联质谱法测定茶叶茶汤中多种农药残留量

目的采用Qu ECh ERS方法和气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)分析技术,建立茶叶茶汤中65种不同极性农药残留量的快速检测方法。方法利用乙腈(含1%乙酸)提取茶叶茶汤样品,分散固相萃取法净化样品,GC-MS/MS检测采用选择反应监测模式(selective reactions monitoring,SRM),灵敏度最高的离子对用作定量。结果 65种农药在3个浓度添加水平上的加标回收率范围是76%~134.6%,相对标准偏差(RSD,n=6)范围为1.0%~18.41%,茶叶样品定量限是0.15~3.0μg/kg,茶汤样品定量限是0.1~1.5μg/kg。结论该方法灵敏度高,准确性好,快速简便,适用于绿茶、乌龙茶、白茶和红茶中多种农药残留量的检测。     

气相色谱-三重串联四极杆质谱法测定粮谷中169种农药的残留量

建立了粮谷中169种农药多残留的气相色谱-三重串联四极杆质谱(GC-MS/MS)的检测方法。样品经改进的QuEChERS净化处理,气相色谱分离,串联四级杆质谱多反应监测方式检测。结果表明,169种农药在粮谷中的检出限为0.3～13.0μg/kg,定量限为1.0～40.0μg/kg,线性范围在0.005 mg/L～2.0 mg/L之间,线性相关系数大于0.99,平均回收率在65.3%～143.6%之间,97%的农药相对标准偏差小于20%,该方法具有前处理简单、净化效果好、灵敏度高的特点,适用于粮谷中多组分农药残留的快速确认和定量检测。     

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.