分散固相萃取-气相色谱串联质谱法检测大米中35种农药残留

目的 建立分散固相萃取-气相色谱串联质谱法测定大米中35种农药残留的分析方法。方法 采用QuEChERS方法对样品进行前处理。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(C18)分散固相材料净化后上机测定。用气相色谱-三重四极杆串联质谱仪进行多农残检测。结果 35种农药在50~1000 ng/mL之间呈良好的线性关系, 相关系数r均大于0.99。在0.02、0.1、0.2 mg/kg加标水平下, 35种农药的平均回收率为75.4%~128.6%, 相对标准偏差(relative standard deviation, RSD)为0.6%~10.8% (n=6)。结论 该方法快速、准确、灵敏, 适合测定大米中多种农药残留。     

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。     

多壁碳纳米管分散固相萃取净化-气相色谱三重四级杆质谱联用同时测定桂皮中10种有机磷农药

建立一种多壁碳纳米管分散固相萃取净化-气相色谱三重四级杆质谱联用同时测定桂皮中10种有机磷农药的检测方法。样品经乙腈提取,以MWCNTs、PSA和MgSO_4净化,离心、过滤后经气相色谱三重四级杆质谱测定,外标法定量。结果表明,10种有机磷农药在0.01~1.0μg/mL范围内具有良好的线性。加标回收率为78.3%~105.2%,相对标准偏差(n=5)为1.6%~9.2%,方法检出限为0.001~0.010mg/kg。该方法操作简单快捷、准确、检测成本低,能满足桂皮中有机磷农药残留的检测要求。     

分散固相萃取-分散液液微萃取-气相色谱-质谱联用法测定中草药类保健食品中29种有机磷农药残留

目的建立测定中草药类保健食品中有机磷农药残留的分散固相萃取-分散液液微萃取-气相色谱-质谱联用法。方法样品经含0.5%甲酸的乙腈超声提取,上清液经含无水硫酸镁、N-丙基乙二胺(PSA)、C18的分散固相萃取管(d-SPE)净化后,采用分散液液微萃取(DLLME)步骤,用氯仿萃取、浓缩目标化合物。结果在最优条件下,线性范围为0.05~1.00μg/ml,线性相关系数在0.999以上,检出限(LOD)为0.3~3.0μg/kg,29种有机磷农药的平均加标回收率在70.3%~107.5%之间,相对标准偏差均10%。结论该方法具有简便快速、准确灵敏、萃取效率高等特点,可用于中草药类保健食品中有机磷农药残留的检测。     

超高效液相色谱-串联质谱法测定茶叶中6种农药残留

目的建立超高效液相色谱-串联质谱法测定茶叶中吡虫啉、多菌灵、啶虫脒、水胺硫磷、三唑磷和甲基异柳磷6种农药残留的方法。方法样品经乙腈提取,NH_2固相萃取小柱富集、净化,以二氯甲烷-甲醇(9:1,V:V)为洗脱溶液;样品经浓缩定容后,采用Thermo C_(18)(2.1 mm×50 mm,1.7μm)色谱柱分离,流速为0.3 mL/min,以水-甲醇-乙腈为流动相进行梯度洗脱,采用超高效液相色谱-串联质谱法多反应监测模式进行测定,采用基质标准溶液外标法定量。结果 6种农药在0.005~0.25μg/mL浓度范围内呈良好的线性关系,相关系数为0.9973~0.9998。当添加水平为0.005、0.025、0.25 mg/kg时,6种农药在茶叶中的加标回收率为72.4%~106.6%,相对标准偏差为1.6%~10.0%。方法定量限为0.5~5μg/kg。结论该方法操作简单、快速,可适用于茶叶中吡虫啉、啶虫脒、多菌灵、水胺硫磷、三唑磷和甲基异柳磷6种农药残留的测定。     

固相萃取净化-气相色谱质谱法测定茶叶中22种禁用农药残留量

建立了测定茶叶中22种禁用农药残留量的气相色谱-质谱联用分析方法。茶叶样品经乙腈均质提取后,经石墨化碳-氨基复合固相萃取小柱净化后,采用气相色谱质谱联用仪在选择离子监测模式下进行定性定量。结果表明,22种农药在0.05~1.00μg/m L范围内的标准工作曲线相关系数大于0.99;在1.00、0.25和0.025 mg/kg浓度添加水平下,22种农药的回收率在65%~120%之间,相对标准偏差(RSDs)小于10%;方法检出限为0.001~0.031 mg/kg。该方法准确、快速、稳定,适合实际检测需要。     

液相色谱-串联质谱法同时测定中草药保健食品中15种有机磷和氨基甲酸酯类农药残留

目的建立高效液相色谱-串联质谱法同时测定中草药保健食品中15种有机磷和氨基甲酸酯类农药残留。方法样品经乙腈提取后,高速离心,经分散型固相萃取小柱净化。采用Atlantis C_(18)(2.1 mm×100 mm,3μm)柱,以0.1%甲酸-乙腈为流动相,梯度洗脱分离。质谱采用正离子模式(electrospray ionization,ESI+),多反应监测模式(multiple reaction monitoring,MRM)进行检测,基质曲线外标法定量。结果该方法对15种农药残留的线性范围为0.001~0.1μg/mL,线性相关系数r≥0.993,加标回收率为82.7%~113.3%,相对标准偏差为2.7%~10.6%,检出限为0.8~24.6μg/kg。结论本方法操作简单、快捷,适用于中草药保健食品中15种有机磷和氨基甲酸酯类农药残留的同时检测,为保健食品质量控制提供依据。     

GC-MS/MS法测定铁皮石斛中19种农药残留

建立固相萃取-气相色谱-三重四极杆串联质谱法测定铁皮石斛中19种农药残留的分析方法。石斛样品经乙腈提取,经ENVI-Carb/Florisil固相萃取小柱进行净化后,采用气相色谱-三重四极杆串联质谱法在多反应监测(MRM)模式下测定,外标法定量。19种农药成分在10μg/L~200μg/L范围内有良好的线性关系,相关系数在0.993 1~0.999 8范围内;19种农药成分在3个添加水平下(10、100、200μg/L),加标回收率范围为82.83%~109.29%,RSD%(n=5)为1.43%~5.74%;各农药成分的检出限均小于0.58μg/L。该方法可应用于石斛中多种农药残留的同时检测。     

Dis-SPE-HPLC-DAD检测水果中有机磷和氨基甲酸酯类农药

建立了高效液相色谱-二极管阵列检测水果中涕灭威、西维因、异丙威、仲丁威、马拉硫磷等5种有机磷和氨基甲酸酯农药的方法。前处理方法采用分散固相萃取,样品以乙腈提取,经无水硫酸镁和氯化钠盐析,PSA净化后,进行HPLC-DAD检测。以甲醇/水(体积比70/30)为流动相,流速1 m L/min。DAD检测器的波长设定为210 nm。5种农药在0.04μg/m L~4μg/m L范围内线性相关系数均高于0.99,检出限在0.057μg/m L~0.60μg/m L之间。样品在0.2、0.4、2μg/m L的加标水平时,平均回收率为73.32%~93.12%,RSD为3.46%~9.36%(n=6)。与传统固相萃取方法相比,分散固相萃取具有简便、省时、高精确度和高回收率的优点,可以作为水果中农药残留的日常检测方法。     

LC-MS/MS测定大米中噻虫嗪农药残留

利用LC-MS/MS建立大米中噻虫嗪农药测定的方法。试样中噻虫嗪农药残留在超声波振荡条件下用乙腈提取,经C18和PSA进行分散固相萃取净化,经液相色谱质谱联用仪检测。方法的检出限为0.1μg/kg,回收率为93.5%~101.2%,相对标准偏差为3.12%~5.84%。     

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.