溶剂吸收-气相色谱-质谱法测定食用菌中二硫代氨基甲酸酯类农药

目的建立食用菌中二硫代氨基甲酸酯类农药残留的溶剂吸收-气相色谱-质谱测定方法。方法样品在氯化亚锡盐酸溶液中加热发生消化反应,生成二硫化碳,冷却后用正己烷萃取出二硫化碳,经Hp-VOC色谱柱(60 m×0.20 mm,1.12μm)分离,选择离子监测(SIM)模式气相色谱-质谱进行检测,外标标准曲线法定量。结果食用菌中添加0.025、0.05、0.25 mg/kg 3个水平的标准溶液,回收率的范围为94.8%～109%,相对标准偏差为3.7%～5.5%(n=3)。检出限为0.01 mg/kg,定量限为0.02 mg/kg。结论该方法具有操作简单、准确度高和精密度好等优点,可适用于食用菌中二硫代氨基甲酸酯类农药残留的测定。     

GC-MS法测定植物性样品中二硫代氨基甲酸酯类农药残留

建立测定植物性样品中二硫代氨基甲酸酯类农药残留的气相色谱-质谱联用仪法(GC-MS)。取匀浆的植物性样品,加入氯化亚锡-盐酸溶液,密闭水浴反应后,用正己烷萃取,GC-MS分析测定。并测定标准系列溶液,绘制标准曲线,其相关系数均大于0.999。检出限为0.003 μg/g,定量限为0.01 μg/g。平均回收率在95.9%～99.8%,相对标准偏差为1.12%～5.12%。该方法适用于植物性样品中二硫代氨基甲酸酯类农药残留的测定。     

溶液吸收-气相色谱质谱测定天麻中二硫代氨基甲酸酯(盐)类农药的含量

目的 建立溶液吸收-气相色谱质谱检测法测定天麻中二硫代氨基甲酸酯(盐)类农药残留量的方法。方法 目标物在加热条件下经溶液吸收, 转化为二硫化碳, 经正己烷萃取, 采用气相色谱质谱法间接测定二硫代氨基甲酸酯(盐)类农药含量。对云南省16州市采集的55件天麻中的二硫代氨基甲酸酯(盐)类农药的残留量进行统计分析。结果 该方法的线性范围为0.02~10 mg/kg, 相关系数0.9996, 定量限0.010 mg/kg, 空白基质加标回收率90.5%~105.0%, 相对标准偏差(relative standard deviation, RSD)为4.77% (n=6)。55件天麻样品检出率23.6%, 平均值0.021 mg/kg, 含量范围为ND~0.275 mg/kg。结论 该方法简便、快速、灵敏, 适合天麻中二硫代氨基甲酸酯(盐)类农药的测定。采集的天麻样品中二硫代氨基甲酸酯(盐)类农残含量水平总体较低。     

吉林省食用菌中二硫代氨基甲酸酯类农药残留监测及结果分析

目的建立气相色谱-质谱法测定菌类中二硫代氨基甲酸酯类农药的含量,了解吉林省内几种菌类食品中二硫代氨基甲酸酯的残留情况。方法样品在加热密闭的顶空瓶中进行前处理,进入气相色谱-质谱仪进行检测,以CS_2为检测目标物,程序升温,选择性离子监测,外标法定量。结果食用菌类中二硫代氨基甲酸酯类农药检出限为0.005 mg/kg,定量限为0.015 mg/kg,在0.02～0.5 mg/L范围内线性关系良好(r0.9990)。部分菌类食品中存在二硫代氨基甲酸酯的残留检出率为25.2%,检出浓度为0.011～0.098mg/kg,其中香菇的检出率最高为57.89%。结论吉林省内菌类食品中含有一定量的二硫代氨基甲酸酯的残留,均低于GB2763-2016中规定的最大残留量1mg/kg,但是检出率较高,需要加强日常监管。     

超高效液相色谱-串联质谱法测定果蔬中4种乙撑二硫代氨基甲酸酯农药残留

目的 建立超高效液相色谱-串联质谱法(UPLC-MS/MS)测定蔬菜、水果中4种乙撑二硫代氨基甲酸酯类农药残留量的方法。方法 试样采用L-半胱氨酸盐酸盐和碱性EDTA-Na₂溶液进行提取，碘甲烷衍生，QuEChERS原理净化浓缩，UPLC-MS/MS对乙撑二硫代氨基甲酸酯类农药衍生物进行测定，外标法定量。结果 水果的检出限为5μg/kg，蔬菜的检出限为10μg/kg，相关系数大于0.998，添加回收率的范围为82.3%～115.1%，相对标准偏差为2.3%～6.9%。结论 本文所建立的方法能够满足多种水果和蔬菜中乙撑二硫代氨基甲酸酯类农药快速准确检测。     

QuEChERS-高效液相色谱-串联质谱法检测蔬菜中二硫代氨基甲酸酯(盐)残留量

文章建立了柱前衍生结合QuEChERS技术测定蔬菜中二硫代氨基甲酸酯(盐)类(Dithiocarbamates, DTCs)农药残留量的分析方法。蔬菜样品中的二硫代氨基甲酸酯(盐)类农药在碱性乙二胺四乙酸二钠溶液中转化为水溶性钠盐，经碘甲烷衍生后用QuEChERS技术提取和净化，以0.05%甲酸水溶液-乙腈作为流动相在C₁₈色谱柱上梯度洗脱与分离，在ESI⁺模式下采用多反应监测(Multiple reaction monitoring,MRM)测定，基质匹配标准曲线外标法定量。结果表明，二硫代氨基甲酸酯(盐)类农药在2.0～500μg/L之间具有良好的线性关系，相关系数均大于0.999。在普通白菜、茄子、黄瓜、豇豆、胡萝卜、韭菜6种不同类别的蔬菜中添加不同水平二硫代氨基甲酸酯(盐)类农药时，回收率范围在79.6%～109.5%，相对标准偏差为0.7%～10.9%。方法的检出限(以CS₂计)为0.3～1.1μg/kg，定量限(以CS₂计)为1.2～2.8μg/kg。该方法简便、快速、准确，可用于蔬菜中...     

烟草中二硫代氨基甲酸酯农药残留量的测定

为提高烟草中农药残留量的检测效率,建立了一种快速测定二硫代氨基甲酸酯类农药的方法.在密闭系统中,试样中的二硫代氨基甲酸酯在加热、超声条件下与还原性酸溶液反应,分解产生的二硫化碳经过异辛烷吸收后用气相色谱/质谱联用法(GC/MS)检测,以二硫化碳的含量表示二硫代氨基甲酸酯残留量.结果表明:方法的回收率在90.4%～106...     

酶抑制-数字图像比色法检测和鉴别食品中二硫代氨基甲酸酯、氨基甲酸酯和有机磷类农药残留

目的 建立一种酶抑制-数字图像比色法检测和鉴别食品中二硫代氨基甲酸酯、氨基甲酸酯和有机磷类农药残留的分析方法。方法 采用简单的胶带黏贴剥离方式,结合低共熔溶剂洗脱对食品样品中的农药进行高效提取。基于二硫代氨基甲酸酯、氨基甲酸酯和有机磷类农药对酪氨酸酶的抑制活性,使酪氨酸酶对酚类物质的氧化能力降低,进而影响酚类物质与氯化铁生成有色物质的反应,建立酪氨酸酶、酚类物质和氯化铁的比色阵列传感器,实现农药的残留分析,并结合主成分分析实现多种农药的区分。结果 本研究建立的酶抑制-数字图像比色法对番茄、苹果和玉米中福美锌残留在0.008～8.000mg/kg的范围内线性良好,检出限为0.003 mg/kg,定量限为0.008 mg/kg,回收率为75.2%～94.9%,相对标准偏差小于5.0%。结论 本研究建立的酶抑制-数字图像比色法绿色环保、简单高效,且易于推广,适用于蔬菜、水果和谷物等食品样品中农药残留的检测,并且在多种农药的残留分析方面有良好的应用前景。     

高效液相色谱串联质谱测定甘蔗中12种氨基甲酸酯类农药残留

建立了甘蔗中12种常用的氨基甲酸酯类农药残留的高效液相色谱串联质谱(HPLC-MS/MS)检测方法。甘蔗样品用乙腈提取,经QuEChERS方法净化后,采用HPLC-MS/MS进行分析检测,在多反应监测模式(MRM)下,外标法定量,线性良好(r2>0.995),检出限为0.03～0.19μg/kg。分别在样品中添加标准农药样品10、50、100μg/kg水平上进行添加回收率实验,方法的回收率范围为81.3%～108.1%,相对标准偏差为0.8%～4.7%(n=6)。该方法样品前处理简单、快速,分析时间短,灵敏度、准确度和精密度均符合农药残留检测要求,满足甘蔗中氨基甲酸酯类农药残留检测要求。     

用于农药残留现场快速检测的微流控芯片研制

研制一种用于农药残留现场快速检测的微流控芯片。设计制作的一次性高聚物微流控芯片集成进样、酶抑制反应、显色反应及检测单元,结合自制的手持式光度分析检测装置,可以实现对有机磷、氨基甲酸酯类农药的现场、低成本、快速、准确的检测。结果表明：通过在芯片内部固定存储生化试剂,只需一次进样,7 min内即可实现对克百威和乐果的快速检测,最低检出限分别为0.02、0.6 mg/L,对克百威加标回收率为95.0%～103.3%,制作的芯片在1 个月内的稳定性较好。使用微流控农药残留快速检测芯片系统,有望实现全自动检测流程,特别适合于基层非专业人员开展现场、快速、高通量的农药残留筛查。     

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.     

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.     

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.     

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.