气相色谱-串联质谱测定韭菜中的氟氯氰菊酯残留量

目的建立了韭菜中测定氟氯氰菊酯的气相色谱-串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)分析方法。方法样品用乙腈匀浆提取、盐析、石墨化碳黑/氨基混合型固相萃取柱净化、乙腈/甲苯(3:1,v:v)洗脱,浓缩定容后检测。目标化合物经SLB-5MS(30 m×0.25 mm×0.25μm)色谱柱分离,采用三重串联四级杆多反应监测模式(multiple reaction monitoring,MRM)进行定性定量分析。结果在0.05~0.50mg/L添加水平时(n=5),氟氯氰菊酯的回收率在78.5%~98.0%之间,相对标准差在3.4%~8.3%之间。方法的线性范围为0.05~0.50 mg/L,决定系数R~20.99,该方法对氟氯氰菊酯的定量限为0.05 mg/kg。,结论该方法能满足韭菜中氟氯氰菊酯残留检测的要求。     

液相色谱-串联质谱法测定毛织物中的氯菊酯防蛀剂

文章建立了一种高效液相色谱-串联质谱法测定毛织物中氯菊酯防虫蛀剂含量的方法。毛织物中的氯菊酯经甲醇浸泡、超声提取、过滤后,利用液相色谱分离氯菊酯异构体,采用质谱-选择离子监测法对其作定量测定。顺、反氯菊酯的标准曲线线性相关系数均大于0.999 2,线性范围为0.01~1μg/m L。该方法对顺式氯菊酯的检出限为0.707 ng/m L、反式氯菊酯为1.645 ng/m L。在2 mg/kg、20 mg/kg的2个添加水平范围内的平均回收率在92.6%~96.9%之间,相对标准偏差(n=7)在0.2%~7.6%之间。与高效液相色谱法相比杂质干扰小,准确性高,检测限更低。     

超高效液相色谱-串联质谱法测定干辣椒中2种新型杀虫剂残留量

目的 建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)测定干辣椒中氰氟虫腙和氯虫苯甲酰胺残留量的分析方法。方法 干辣椒样品经乙腈匀浆提取, 氨基固相萃取小柱净化, 甲醇/水(50:50, V:V)定容, 以反相C18色谱柱(100 mm×2.1 mm, 1.7 μm)分离, 0.1%甲酸-水和甲醇作为流动相进行梯度洗脱, 多反应监测模式下进行超高效液相色谱-串联质谱测定、基质匹配标准溶液外标法定量。结果 2种新型杀虫剂在5~500 μg /L范围内线性关系良好, 相关系数均大于0.999, 定量限为0.008~0.01 mg /kg; 在高、中、低3个加标水平下的回收率为80.4%~94.9%, 相对标准偏差在0.9%~8.7%之间。结论 方法简单、快速、灵敏高、准确可靠, 可操作性强, 适合测定干辣椒中氰氟虫腙和氯虫苯甲酰胺残留量。     

QuEChERS-气相色谱-串联质谱法检测蜂蜜中氟胺氰菊酯残留量

目的 建立QuEChERS-气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry, GC-MS/MS)测定蜂蜜中氟胺氰菊酯残留量的分析方法。方法 样品采用乙腈提取, 经QuEChERS (quick, easy, cheap, effective, rugged, safety)净化, 用气相色谱-串联质谱法在全扫描(SCAN)和选择反应监测(selective reaction monitoring, SRM) 2种扫描方式下对蜂蜜中的氟胺氰菊酯进行检测。结果 在氟胺氰菊酯浓度为0.02~1.0 μg/mL浓度范围内, 线性关系良好, 相关系数r2=0.9993, 检出限为2 μg/kg, 加标回收率在92.00%~93.40%, 相对标准偏差为4.79%~7.83%。结论 该方法简便、准确, 且毒性有机溶剂使用较少, 对环境友好, 可用于检测蜂蜜中氟胺氰菊酯的残留量。     

QuEChERS-高效液相色谱法同时检测茶鲜叶和乌龙茶中4种农药残留

建立了同时检测茶鲜叶和乌龙茶中茚虫威、毒死蜱、高效氯氟氰菊酯及高效氰戊菊酯农药残留的Qu ECh ERS-高效液相色谱(HPLC)方法。茶鲜叶和乌龙茶样品以乙腈为提取溶剂经超声波辅助萃取,提取液采用N-丙基乙二胺(Primary secondary amine,PSA)、石墨化炭黑(Graphitized carbon black,GCB)和C18联合净化,Agilent ZORBAX-XDB C18色谱柱分离,甲醇和水梯度洗脱,分别在310、230、220 nm与230 nm波长下检测茚虫威、毒死蜱、高效氯氟氰菊酯和高效氰戊菊酯。结果表明:该方法在0.1、1.0、5.0 mg/kg 3个加标水平下,4种农药的平均回收率为79.1%~109.4%,相对标准偏差(n=6)为1.5%~8.8%,检测限在(0.02~0.05)mg/kg之间,定量限在(0.04~0.09)mg/kg之间,满足茶鲜叶和乌龙茶中上述4种农药残留分析的要求。     

凝胶渗透色谱净化联合气相色谱-串联质谱法同时测定番石榴中3种农药残留

目的建立一种同时测定番石榴中3种常用农药的凝胶渗透色谱净化联合气相色谱-串联质谱法(gel permeation chromatography-gas chromatography-tandem mass spectrometry,GPC-GC-MS/MS)分析方法。方法番石榴样品经乙腈提取,凝胶渗透色谱净化,毛细管气相色谱柱分离后,采用三重串联四极杆多反应监测模式测定。结果 3种农药在0.05~0.50 mg/L范围内线性关系良好,相关系数均不低于0.9990;毒死蜱、克螨特、氟氯氰菊酯的定量限分别为0.002、0.005、0.01 mg/kg;在0.05、0.10、0.50 mg/kg 3个加标水平下,3种农药的回收率在83.3%~104.8%之间,相对标准差为2.9%~7.9%。结论该方法处理简便,能满足番石榴中3种常用农药毒死蜱、克螨特、氟氯氰菊酯残留检测的要求。     

全自动固相萃取-气相色谱-三重四级杆质谱法检测蔬菜中23种农药残留

目的建立蔬菜中有机磷类、拟除虫菊酯类共23种农药残留的分析方法。方法样品加丙酮-二氯甲烷(1∶1,V/V)混合溶剂提取后经全自动固相萃取仪净化,采用气相色谱-三重四级杆串联质谱的多反应监测模式进行检测,内标法定量。结果 23种农药在0.05~0.80 mg/L范围内线性良好,相关系数均大于0.993 3;加标回收率在75.0%~105.5%之间;方法的检出限为0.02~0.70 mg/kg。在少量蔬菜样品中发现氯氰菊酯和氯氟氰菊酯超标。结论该方法适用于蔬菜中多种农药残留的快速筛查测定。     

液相色谱串联质谱法快速测定动物组织中克百威及其代谢产物残留量

建立快速测定动物组织中克百威及其代谢产物三羟基克百威残留量的液相色谱串联质谱(liquid chromatography?with?tandem?mass spectrometry,LC-MS/MS)分析方法。动物组织样品中残留物利用乙腈提取,提取后溶液经N-丙基乙二胺(primary secondary amine,PSA)和C18材料净化,净化后的提取液经氮吹后用0.1%甲酸溶液-乙腈(50∶50,V/V)溶解,进行LC-MS/MS分析。采用Acquity BEH C18色谱柱分离,用0.1%甲酸溶液-乙腈作为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,多反应监测(multiple reaction monitoring,MRM)模式检测,内标法定量。克百威和三羟基克百威分别在0.05~25.0μg/L和0.25~50.0μg/L质量浓度范围内具有良好的线性关系,线性相关系数均大于0.999;在动物组织(猪肉和牛肉)中克百威和三羟基克百威的方法检测限分别为0.10μg/kg和0.50μg/kg,定量限分别为0.25μg/kg和1.0μg/kg。添加范围为0.25~10μg/kg时,平均回收率在95.7%~107.0%之间,批内相对标准偏差(relative standard deviation,RSD)在3.2%~5.9%之间,批间RSD在4.5%~6.6%之间。该方法能满足动物肉组织中克百威及其代谢产物残留量快速分析的要求。     

吸附剂提取-GC/MS法测定农田水中的8种常用农药

建立气相色谱-质谱(GC-MS)法同时检测农田水中8种常用农药(毒死蜱、乙酰甲胺磷、丙溴磷、高效氯氟氰菊酯、溴氰菊酯、氯氰菊酯、噻虫嗪、氟虫氰)的方法。农田水样品经吸附剂提取、净化等预处理,用乙腈-冰乙酸(9︰1, V/V)作为提取液,无水硫酸镁和十八烷基硅烷(C18)粉末净化,净化液用丙酮定容至1.0 mL, 0.22μm滤膜过滤,经气相色谱仪-质谱联用仪定性定量检测。结果表明, 8种常用农药在0.05～25μg/m L范围内线性关系良好, R2均小于0.995;检出限在0.008～0.020 mg/kg之间,加标回收率(低点0.05 mg/kg、中点1.0 mg/kg、高点10.0 mg/kg)均在83.6%～105.5%之间;重复性RSD为3.42%～4.92%(n=6),精密度RSD为1.69%～2.64%(n=6)。该方法具有前处理提取快速、检出限低、检测结果准确等优点,可用于农田水中常用农药的监测。     

金针菇中6种拟除虫菊酯类农药多残留的测定

建立联苯菊酯、甲氰菊酯、高效氯氟氰菊酯、高效氯氰菊酯、氰戊菊酯和溴氰菊酯6种拟除虫菊酯类农药在金针菇中的多残留分析方法。样品以乙腈为提取溶剂,弗罗里硅土柱层析净化,气相色谱-电子捕获法测定。该检测条件下,联苯菊酯、甲氰菊酯和高效氯氟氰菊酯在0.005～0.50mg/L、高效氯氰菊酯、氰戊菊酯和溴氰菊酯在0.01～1.00mg/L的范围内具有良好的线性关系,线性方程的决定系数大于0.996。添加回收实验结果表明,供试农药在添加量范围平均回收率为85.54%～102.27%,变异系数为1.24%～9.58%,联苯菊酯、甲氰菊酯和高效氯氟氰菊酯的最低检测限为5μg/L,高效氯氰菊酯、氰戊菊酯和溴氰菊酯的最低检测限为10μg/kg。该方法的准确性、精确性和灵敏度均满足农药残留分析的要求。     

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.     

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.     

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.