LC-MS/MS测定茶叶中吡虫啉和啶虫脒残留量

茶叶采用乙腈提取,C18,SPE小柱净化,液相色谱-串联质谱法测定茶叶中吡虫啉和啶虫眯。色谱柱为ZORBAX,XDB C18,5μm,4．6mm×150mm,流动相为乙腈-0．1％甲酸梯度洗脱。结果表明：该方法定性、定量准确,灵敏度高,最低检出限为0.01mg／kg,加标回收率吡虫啉80％～90％,啶虫脒76％-88％,RSD（n=5）为吡虫啉为6．84％～7．25％,啶虫眯为7．90％～9．92％,具有操作简单、速度快、准确度高、色谱分离效果好、对环境污染少的特点。     

固相萃取-高效液相色谱-串联质谱法测定茶叶中啶虫脒、吡虫啉和氟虫腈残留量

目的建立茶叶中吡虫啉、啶虫脒和氟虫腈三种农药残留的固相萃取-高效液相色谱-串联质谱测定方法。方法样品用水浸泡,乙腈提取,经石墨化碳-氨基复合固相萃取小柱净化,采用Agilent Eclipse AAA色谱柱分离,以0.1%乙酸水溶液和乙腈为流动相梯度洗脱,正、负离子切换扫描,多反应监测(MRM)模式检测,外标法定量。结果在3个添加水平下,吡虫啉、啶虫脒和氟虫腈的平均回收率分别为78.8%~91.5%,81.3%~92.8%,和72.8%~90.0%;相对标准偏差分别为2.6%~10.6%,3.7%~6.6%和3.6%~7.4%。啶虫脒、吡虫啉和氟虫腈的检出限均为0.5μg/kg,定量限为2μg/kg。结论建立的方法简便、快速,灵敏度高,可满足出口茶叶中吡虫啉、啶虫脒和氟虫腈残留同时检测的要求。     

高效液相色谱-串联飞行时间质谱法测定茶叶中6种农药的残留量

建立了茶叶中噻嗪酮、毒死蜱、啶虫脒、吡虫啉、乐果、多菌灵等6种农药残留量的高效液相色谱-串联飞行时间质谱检测方法。茶叶样品经酸化乙腈提取,基质分散固相萃取净化。经高效液相色谱分离后进入飞行时间质谱检测。6种农药浓度在1～50μg/kg下线性关系良好,相关系数R2在0.995～0.999之间,检测限在0.01～1μg/kg之间,回收率在80%～102%之间,相对标准偏差(RSD)在4%～6%之间。该方法快速、准确、灵敏度高,能够满足茶叶中多种农药残留的定性、定量检测需求。     

超高效液相色谱-质谱联用法测定山野菜中5种农药的残留

建立超高效液相色谱-质谱联用法[ACQUITY UPLC/Xevo TQ-S]测定人工栽培山野菜中啶虫脒、吡虫啉、多菌灵、嘧霉胺、苯醚甲环唑5种农药残留。以乙腈为提取溶剂,采用多重反应离子监测(MRM)模式,ACQUITY UPLC BEH C18为分析色谱柱、0.1%甲酸乙酸铵-乙腈为流动相,对样品进行检测分析。结果表明:5种农药在0.0005~2.0000 mg/L范围内与峰面积呈良好线性关系,相关系数在0.9947~0.9999之间。在农药混合标准溶液0.005~0.200 mg/kg的水平下,添加回收率均在73.43%~115.84%之间,相对标准偏差为2.04%~18.19%。检出限在0.020~0.510μg/kg范围内;定量限在0.066~1.699μg/kg范围内。本方法操作简单、快捷、准确度和精密度高,可应用于山野菜中5种农药残留测定。     

凝胶渗透色谱-超高效液相色谱-串联质谱测定茶叶中吡虫啉和啶虫脒

建立用凝胶渗透色谱-超高效液相色谱-串联质谱仪测定茶叶中吡虫啉和啶虫脒残留的方法。样品经乙酸乙酯-环己烷（1∶1,V/V）溶液涡旋混匀后超声提取,经凝胶渗透色谱净化后,采用超高效液相色谱-串联质谱仪测定。结果显示,2 种农药在0.5～100 μg/L范围内线性良好,相关系数R2均大于0.99。吡虫啉和啶虫脒的检出限分别为2.0 μg/kg和1.0 μg/kg,定量限分别为5.0 μg/kg和3.0 μg/kg。吡虫啉和啶虫脒在3 个水平的加标平均回收率为76.94%～91.68%,相对标准偏差为2.67%～7.90%。     

液相色谱-串联质谱法测定茶叶中的11种农药残留

目的建立液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)测定茶叶中11种农药残留的分析方法。方法样品经乙腈提取,经石墨化炭黑/N-丙基乙二胺复合型固相萃取柱(graphite carbon black/primary secondary amine,GCB/PSA)净化,用液相色谱-串联质谱法测定。结果 11种农药浓度在0.005~0.20μg/m L范围内线性良好,线性相关系数均大于0.997,在0.01、0.05和0.10 mg/kg的添加水平下,回收率为66.0%~100.0%,相对标准偏差为2.2%~10.0%。结论本方法简便、快速、准确,适用于茶叶样品中11种农药残留量的检测。     

高效液相色谱-串联质谱法测定中草药中多种 新烟碱类农药的残留量

目的建立液相色谱-串联质谱分析法同时测定中草药夏枯草、野菊花、金银花、苏银花中噻虫嗪、氯噻啉、吡虫啉、啶虫脒、噻虫胺、噻虫啉6种新烟碱类农药残留量。方法样品中的6种新烟碱类杀虫剂经乙腈提取,QuEChERS方法净化后,液相色谱-串联质谱法分离和测定,外标法定量。结果方法检出限为0.1～4.8μg/kg,在方法的检测限与200 ng/mL测定范围内有良好的线性关系(r0.9990),在所添加5个水平浓度下,方法的回收率在70.4%～108.3%,相对标准偏差在1.0%～8.8%。结论该方法准确、简单、快速,适用于中草药中多种新烟碱类农药的同时检测。     

LC-MS/MS法测定枸杞中啶虫脒、吡虫啉农药残留的方法学研究

目的:枸杞是一种药食两用的中药材,人们经常食用枸杞来提高身体免疫力。本论文以枸杞为研究对象,建立了液相色谱-串联质谱法,以同时测定啶虫脒、吡虫啉农药残留量。     

基于动态多反应监测模式下的高效液相色谱-串联质谱法同时测定枸杞中44种农药残留

目的:建立一种基于动态多反应监测模式同时检测枸杞中44种农药残留的高效液相色谱-串联质谱的分析方法。方法:样品经10 mL超纯水复水,用0.1%甲酸-乙腈提取,经PSA、C₁₈、MgSO₄填料净化,T3色谱柱分离,0.1%甲酸水和乙腈流动相体系梯度洗脱,在正离子模式下采用动态多反应监测模式(d-MRM)检测,基质匹配外标法定量。结果:44种农药在0.002~0.200 mg/L范围内线性关系良好(R2>0.9943),方法检出限范围为0.01~3.30 μg/kg,3个添加水平的回收率为60.2%~115.3%,相对标准偏差为0.63%~8.27%。测定了市售枸杞样品20批,共检出农药残留14种,其中多菌灵、啶虫脒、吡虫啉的检出率高达95%。结论:该方法操作快速、简便、准确、可靠,适用于枸杞中44种农药残留的同时检测。     

UPLC-MS/MS检测果蔬饮料中痕量吡虫啉

建立一种快速、有效的超高效液相色谱-串联质谱法测定果蔬饮料中痕量吡虫啉农药残留的方法。样品经0.1%醋酸-乙腈提取后,采用氨基固相萃取小柱进行净化和富集。采用Waters Atalantis T3色谱柱(2.1 mm×150 mm,3μm)分离,以0.1%甲酸-乙腈为流动相的梯度洗脱模式下,吡虫啉标准在0.5 ng/mL~50.0 ng/mL浓度范围内线性良好,相关系数r~2为0.999,检出限为0.15μg/kg,定量限为0.50μg/kg,加标回收率达到93.2%~96.9%。     

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.