利用气液微萃取技术联用气相色谱-质谱法检测谷类中27种残留农药

目的建立气液微萃取技术(gas-liquid microextraction,GLME)联用气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)快速检测谷类中的27种农药残留的方法。方法精确称量0.5 g谷类样品,用0.5 mL二氯甲烷溶剂超声萃取15 min,离心4 min后取上清液100μL,利用气液微萃取(GLME)对27种农残萃取、净化和浓缩,结合内标法确保结果的准确性。结果 27种农药在0.001～1.0mg/kg浓度范围内线性良好,相关系数在0.9990～0.9999,检出限为0.002～0.026 mg/kg,定量限为0.0007～0.086 mg/kg,平均回收率为71.2%～124.4%(n=3),相对标准偏差在0.2%～18.8%之间。结论本方法操作简便方便、准确度高、重现性好,适用于食品安全现场检测和快速检测,对于保障我国食品安全构建完整的食品安全检测体系具有重大意义。     

凝胶渗透色谱-气相色谱-质谱法测定食用植物油中120种农药残留量

本实验建立了气相色谱-质谱法(GC-MS),同时测定植物油中120种农药的多残留分析方法。样品用正己烷溶解,乙腈萃取,凝胶渗透色谱(GPC)净化,GC-MS测定,外标法定量。方法定量下限检出限(S/N≥10)为0.005~0.100 mg/kg,在加标水平为0.05 mg/kg时,方法回收率为67.1%~120%,相对标准偏差RSD在20%以内。     

SPME-GC-MS法测定人参中6种有机氮农药残留

采用丙酮提取-固相微萃取(SPME)-气相色谱质谱法(GC-MS),建立人参中灭多威、涕灭威、克百威、甲萘威、异丙威和敌菌丹等6种有机氮农药残留量检测方法,并优化SPME正交试验条件(萃取温度、萃取时间、萃取头和搅拌速度)。结果表明,在0.05~1.0μg/mL浓度范围内,6种有机氮农药的峰面积与相对应的浓度呈现出良好的线性关系,相关系数R~2≥0.999;方法检出限在0.001~0.01 mg/kg;在0.05,0.5和1.0 mg/kg 3种加标浓度中,加标回收率在84.6%~102.4%,相对标准偏差(n=6)在1.2%~6.4%。该方法有效减小了人参中生物内源性大分子物质的干扰,准确度高、精密度好、检出限低,且缩短了农药检测时间,提高了农药分析效率,可满足人参中农药残留检测的要求。     

分散固相萃取净化-气相色谱-质谱联用法测定茶叶中7种杀螨杀虫类农药残留

目的建立茶叶中7种农药残留的快速检测方法。方法采用分散固相萃取净化,气相色谱-质谱法(gas chromatography-mass spectrometry,GC-MS)测定茶叶中噻螨酮、噻嗪酮、哒螨灵、喹瞒醚、苯醚甲环唑、联苯菊酯和氟氰戊菊酯7种农药的残留。结果 7种农药在0.05~5.00 mg/kg范围有良好的线性关系,相关系数均大于或等于0.9995。3个浓度的平均加标回收率为70%~115%,相对标准偏差为5.0%~13.2%;方法检出限(limit of detection,LOD)为0.005~0.05 mg/kg,定量限(limit of quantitation,LOQ)为0.015~0.15 mg/kg。采用此方法抽检了我国不同地区市场上的110批次的茶叶样品,其中有15批次样品检出联苯菊酯,含量在24~1640μg/kg之间;有4批次样品中检出噻嗪酮,含量在35~150μg/kg之间;3批次样品检出哒螨灵,含量在70~200μg/kg之间。结论本方法符合农药残留分析标准的要求,可用于茶叶中7种农药残留的快速检测和确证分析。     

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。     

ASE萃取/GPC-SPE净化/GC-MS法测定茶叶中的有机磷残留

建立加速溶剂萃取-凝胶渗透色谱/固相萃取净化-气质法测定茶叶中的有机磷残留的分析方法。样品用丙酮-二氯甲烷(1∶1)作为溶剂,加速溶剂提取,提取液经过凝胶渗透色谱除去大分子杂质后,再经过Carb/NH2柱净化后供GC-FPD和GC-MS分析。方法检出限为为0.001mg/kg~0.0075mg/kg,在加标水平为0.050mg/kg时,回收率为76.3%~94.6%,相对标准偏差为2.4%~8.1%。方法具有自动化程度高、萃取效率高、净化效果好、精密度好,分析快速等优点,适用于茶叶中有机磷残留的日常检测工作。     

QuEChERS-气相色谱质谱法同时测定三七中20种农药残留

目的 建立QuEChERS-气相色谱-质谱联用法(gas chromatography mass spectrometry, GC-MS)同时测定三七中20种农药残留的分析方法。方法 将三七样品用乙腈提取、氯化钠盐析, QuEChERS净化, 采用GC-MS测定, 用保留时间(retention time, RT)和选择离子扫描(selected ion monitor, SIM)定性定量。结果 20种农药在0.1~6.4 μg/mL浓度范围内相相关系数均在0.9994~0.9998之间, 检出限0.002~0.025 mg/kg之间, 加标浓度在0.08~1.60 mg/kg之间的平均回收率在79.4%~104.8%之间, 相对标准偏差为2.01%~5.03%(n=5)。 结论 该方法简单高效, 稳定可靠, 适用于三七中20种农药残留的检测。     

气相色谱法同时测定茶叶中10种有机磷农药残留

目的建立用气相色谱法同时测定茶叶中10种有机磷农药残留的方法。方法采用乙腈做萃取溶剂超声波提取,经CARB/NH2固相萃取小柱净化,用气相色谱法FPD检测器检测茶叶中10种有机磷农药。结果在0.05~1.0 mg/kg浓度范围内具有良好的线性关系,相关系数为0.999 63~0.999 86;在有机磷农药添加浓度为0.02~1.0 mg/kg,回收率80.0%~102.0%,相对标准偏差1.8%~5.8%,最低检出限(LOD,S/N=3)为0.002~0.013 mg/kg。结论建立的气相色谱法是一种操作简单、分离效果好、回收率高、方便快速的检测方法。     

低共熔溶剂固相萃取-高效液相色谱法同时测定粮谷中7种农药残留

目的 建立低共熔溶剂固相萃取-高效液相色谱-紫外可变波长检测法(high performance liquid chromatography-UV variable wavelength detection ,HPlC-UV)测定粮谷中的7种农药(吡虫啉、啶虫脒、多菌灵、除虫脲、灭幼脲、辛硫磷、阿维菌素)残留的测定方法。方法 选用中性氧化铝作为分散剂,与低共熔溶剂(deep eutectic solvents,DESs)组成萃取体系,对样品进行基质分散固相萃取,充分研磨萃取后装入固相萃取小柱用6mL乙腈洗脱,洗脱液吹干,用1mL流动相定容后待测。采用高效液相色谱仪-紫外可变波长检测模式进行测定,流动相为：甲醇-乙腈（7:3）混合溶液-水,色谱柱为ODS-C18柱(250 mm×4.6 mm, 5μm)。结果 在0.05~5.00mg/kg范围内7种农药残留均呈良好的线性关系,相关系数r2大于0.99,方法检出限范围为0.0004~0.0010mg/kg,定量限范围为0.001~0.004mg/kg。7种农药残留的平均回收率范围为86.0%~99.1%, 相对标准偏差(relative standard deviations, RSDs)范围为1.25%~4.65%。结论 本方法简单快捷、成本低廉,设备易满足,且具有良好的准确性、精密度、灵敏度,可用于粮谷中7种农药残留的快速检测。     

分散固相萃取净化-气相色谱法测定大米中4种农药残留

目的建立一种同时测定大米中丁草胺、噻嗪酮、稻瘟灵、溴氰菊酯4种农药残留的分散固相萃取-气相色谱法。方法样品经乙腈提取,盐析后,提取液经N-丙基-乙二胺硅烷(N-propyl-ethylenediamine silane,PSA)和十八烷基硅胶(C_(18))分散固相萃取材料净化后上机测定。优化的色谱条件为:DB-17(30 m×0.25 mm,0.25μm)石英毛细管柱,采用程序升温分离,流速为1.0 mL/min,进样量1.00μL,电子捕获检测器检测。结果 4种农药在0.001~8μg/mL范围内线性良好,相关系数(r)均大于0.999,定量限为0.001~0.08 mg/kg,4种农药平均回收率为89.6%~102.9%,相对标准偏差(RSD)在2.11%~7.81%(n=6)之间。结论该方法操作简便、快速、准确,适用于大米中4种农药残留痕量分析。     

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.     

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.     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.