UPLC-MS/MS法同时测定蔬菜中34种农药残留

采用超高液相色谱-串联质谱联用仪(UPLC-MS/MS)技术建立了同时检测蔬菜中34种农药多残留量的快速检测方法。样品经乙腈提取,浓缩定容后用Qu ECh ERS农残净化管净化,Acquity BEH-C18超高液相色谱柱分离,进入电喷雾串联四极杆质谱进行检测,采用多反应监测(MRM)分析,对液质分离条件进行优化。结果表明34种农药在10 ng/m L~200 ng/m L范围内线性良好(r≥0.993 6)。在10μg/kg~30μg/kg范围内,平均加标回收率在68.7%~116.8%之间,RSD≤12%。该方法检出限为0.001 mg/kg~0.01 mg/kg,测定结果满足蔬菜样品中多残留农药的检测要求。     

QuEChERS-超高效液相色谱-串联质谱法测定桑叶中64种农药残留

目的建立Qu ECh ERS结合超高效液相色谱-串联质谱法测定桑叶中64种农药残留的方法。方法样品经乙腈提取,应用Qu ECh ERS方法进行净化处理。使用Cortecs T3 (2.1 mm×100 mm, 2.7μm)色谱柱,用含0.1%(V/V)甲酸溶液(A)和甲醇(B)为流动相进行梯度洗脱,采用电喷雾电离(electrospray ionization,ESI)和多离子检测模式(multiple reaction monitoring, MRM)进行检测,基质外标法定量。结果 64种农药在0.001~0.050 mg/L范围内线性良好,线性相关系数均大于0.999。在1~10μg/kg添加浓度范围内,回收率为78.0%~94.9%,相对标准偏差为1.1%~5.5%。结论该方法操作简单,灵敏度高,可用于桑叶中农药残留的高通量筛查。     

QuEChERS法结合在线凝胶色谱-气相色谱/质谱法测定人体尿液中34种农药残留

目的建立Qu ECh ERS方法结合在线凝胶渗透色谱-气相色谱/质谱系统用于人尿中34种中高毒农药的快速筛查方法。方法研究Qu ECh ERS各因素如萃取剂、萃取剂用量、萃取次数和净化吸附剂种类对尿样提取净化效果的影响。采用选择离子监测模式,外标法测定人尿中34种农药含量。结果 34种农药在人尿中的检出限为0.05~3.2μg/kg,在0.05μg/g添加水平的平均回收率为81.1%~108.8%,相对标准偏差(RSD)为2.7%~10.4%。结论本法具有操作便捷、通用性强等特点,适用于人尿中34种农药残留的快速筛查与检测。     

采用超高效液相色谱-串联质谱结合改良QuEChERS方法快速分析农产品中天然除虫菊酯6种成分残留

建立了以改良Qu ECh ERS作为前处理方法,结合超高效液相色谱-串联质谱(UPLC-MS/MS)检测农产品中除虫菊酯6种化合物残留量的检测方法。对Qu ECh ERS的净化试剂和萃取盐进行优化,最终选用0.1%醋酸乙腈和d SPE萃取盐包萃取净化。采用多重反应监测(MRM)采集模式测定,除虫菊酯的检出限可达0.2μg/kg,最低定量限可达5.0μg/kg。在0.2~5.0μg/m L内具有良好的线性相关性,R2在0.999以上。除虫菊酯在菠菜、大蒜、大姜、胡萝卜和大头菜基质中的加标回收率为85.6%~117.5%,相对标准偏差(RSD)值为0.4%~8.9%。改良的Qu ECh ERS方法前处理简单,通用性强、回收率高,可以作为检测农产品中该类农药残留的有效前处理方法。     

超高效液相色谱-串联质谱法快速筛查茶叶中的多种农药残留

目的采用超高效液相色谱-串联质谱技术(UPLC-MS/MS)和改进的Qu ECh ERS样品前处理技术,建立茶叶中多种农药残留的快速筛查检测方法。方法样品采用乙腈提取,提取液经N-丙基乙二胺(PSA)、石墨化炭黑(GCB)及茶叶农残检测专用吸附剂(TPT)混合进行分散固相萃取净化(d-SPE)。以BEH C18色谱柱(2.1 mm×100 mm,1.7μm)进行色谱分离,以电喷雾电离串联质谱多反应监测模式(MRM)进行监测。结果以欧盟农药残留参比实验室组织的茶叶中175种农药残留的国际比对考核的茶叶样品进行定性筛查和定量测定,以液相色谱质谱技术从考核茶叶样品中共定性筛查出多菌灵、吡虫清、噻嗪酮等10种农药残留。针对这10种农药进行了定量检测方法的建立和方法验证,10种农药在0.1~20μg/L的浓度范围内呈良好线性,相关系数r0.999,各农药的定量限为0.5~2.0μg/kg,茶叶样品基质的加标回收率在75.7%~105.8%之间,相对标准偏差在2.3%~18.4%之间。定量测得考核的茶叶样品中10种农药的含量在0.021~0.373 mg/kg之间。结论本方法简单、准确、灵敏度高,适用于农产品中农药多残留的快速筛查。     

QuEChERS-高效液相色谱法检测红葡萄酒中多菌灵和甲霜灵杀菌剂残留

建立了以Qu ECh ERS作为前处理方法,采用高效液相色谱(HPLC)检测红葡萄酒中多菌灵和甲霜灵的有效方法。结合考虑2种农药的性质,对Qu ECh ERS的提取盐和净化试剂进行优化,最终选用Na Cl与Na Ac为提取盐,PSA作为吸附净化剂。多菌灵和甲霜灵均在0.2~5.0mg/L范围内具有良好的线性相关性,线性系数在0.999以上。多菌灵和甲霜灵的加标回收率为85.3%~98.34%,相对标准偏差(RSD)值为3.61%~10.22%。Qu ECh ERS方法与其他常规前处理方法相比,通用性强、操作简便、成本低、提取效率高,可以作为检测红葡萄酒中该类农药残留的有效前处理方法。     

超高效液相色谱-串联质谱法测定凉茶中二十种农药残留的含量

目的建立QuEChERS结合超高效液相色谱-串联质谱法(ultra performance liquid chromatographytandem mass spectrometry,UPLC-MS/MS)测定凉茶中包括霜霉威、多菌灵、噻菌灵等20种农药残留的含量。方法 5.00 mL凉茶经过10.00 mL乙腈提取,Qu ECh ERS法萃取,经Shim-pack XR-ODSⅢ色谱柱分离,正离子扫描,多反应监测模式进行质谱分析,外标法定量。结果 20种农残在1.0~100.0 ng/mL范围内具有良好的线性关系。添加水平为5、10、20μg/L时,方法回收率为75.37%~110.21%,相对标准偏差均小于13%(n=6),杀线威、甲萘威、联苯肼酯及噻螨酮的检出限(limits of detection,LODs)为1.0μg/L,其余16种农药LODs均为0.5μg/L。结论本研究建立的方法操作简便、快速准确,适用于凉茶中20种农药残留的快速筛查和定量分析。     

超高效液相色谱-串联质谱法测定凉茶中20种农药残留的含量

目的建立QuEChERS结合超高效液相色谱-串联质谱法(ultra performance liquid chromatographytandem mass spectrometry,UPLC-MS/MS)测定凉茶中包括霜霉威、多菌灵、噻菌灵等20种农药残留的含量。方法 5.00 mL凉茶经过10.00 mL乙腈提取,Qu ECh ERS法萃取,经Shim-pack XR-ODSⅢ色谱柱分离,正离子扫描,多反应监测模式进行质谱分析,外标法定量。结果 20种农残在1.0~100.0 ng/mL范围内具有良好的线性关系。添加水平为5、10、20μg/L时,方法回收率为75.37%~110.21%,相对标准偏差均小于13%(n=6),杀线威、甲萘威、联苯肼酯及噻螨酮的检出限(limits of detection,LODs)为1.0μg/L,其余16种农药LODs均为0.5μg/L。结论本研究建立的方法操作简便、快速准确,适用于凉茶中20种农药残留的快速筛查和定量分析。     

液相色谱-高分辨质谱法快速筛查蔬菜中20种氨基甲酸酯类农药

建立蔬菜中20种氨基甲酸酯类化合物高效液相色谱-静电场轨道阱高分辨质谱分析法。样品经乙腈提取,Qu ECh ERS方法对样品净化后,采用高效液相色谱-静电场轨道阱高分辨质谱法对样品中的目标化合物进行定性分析,外标法定量确证。结果表明:20种氨基甲酸酯类农药在0.005μg/m L~0.1μg/m L范围内线性关系均良好,R2均大于0.99,且所有农药定量限(LOQ)(S/N=10)均低于国际限量要求;在0.01、0.02 mg/kg和0.04 mg/kg的添加水平下,蔬菜中20种氨基甲酸酯类农药的平均回收率介于60%~120%之间,相对标准偏差(RSD)不大于5.0%。该方法较为简单,只需全扫描并提取精确质量数即可进行准确定量,受基质干扰小,能很好的满足我国进出口蔬菜中20种农药限量的严格要求,可以用于蔬菜基质中此20种氨基甲酸酯类农药残留的检测。     

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。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.