气-质谱联用法测定罗汉果中有机磷农药残留

建立气相色谱-质谱联用法(gas chromatography-mass spectrometry,GC-MS)测定罗汉果中11种常用有机磷农药残留量的方法。样品经石油醚-丙酮(体积比2∶1)超声提取,提取物通过活性炭净化后选用HP-5MS毛细管柱对11种有机磷农药进行分离,GC-MS检测,外标法计算含量。11种有机磷农药在线性范围内(10μg/L~750μg/L),相关系数均大于0.999 0,检出限为LOD为0.432μg/L~3.901μg/L。样品3个加标水平(0.125、0.25、0.375μg/g)下,罗汉果中11种有机磷农药回收率均在83.3%~112.4%,相对标准偏差(RSD,n=6)为1.45%~8.28%。     

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。     

QuEChERS结合高效液相色谱串联质谱快速检测速溶茶粉中八种农药残留

利用QuEChERS结合高效液相色谱串联质谱(HPLC-MS/MS)建立了速溶茶粉中8种农药残留(克百威、内吸磷、灭线磷、甲胺磷、辛硫磷、吡蚜酮、硫环磷、氯唑磷)的检测方法。样品经水-乙腈提取,无水MgSO_4和N-丙基乙二胺(PSA)净化后,采用高灵敏度的HPLC-MS/MS检测,优化HPLC-MS/MS条件使8种农药在10 min内完成色谱分离,基质匹配外标法定量。各种农药在添加水平范围内均有良好的线性关系,相关系数(R~2)在0.996 9~0.999 8,定量限(LOQs)为0.2~1μg/kg,平均加标回收率为61%~118%。建立的QuEChERS-HPLCMS/MS方法简单、快速、灵敏度高、准确度高,可以满足对速溶茶粉中多种农药残留同时检测的要求。     

气相色谱-质谱法快速测定葡萄酒中7种有机磷农药

建立了快速同时测定葡萄酒中7种有机磷农药的气相色谱-质谱法(GC-MS法)。葡萄酒样品经除气泡,正己烷提取,离心分层后进样分析。采用HP-5MS色谱柱(30m×250mm,0.25μm)程序升温分离,质谱检测,外标法定量。通过比较不同提取溶剂、不同提取溶剂用量条件下的回收率,优化了前处理方法。结果表明,在0.3-9.0μg/mL范围内,7种有机磷农药的峰面积与质量浓度的线性关系良好(R~2≥0.994),方法检出限为0.02μg/mL,定量限为0.08μg/mL,加标平均回收率为89%以上,相对标准偏差均小于9.8%(n=6)。本方法准确可靠,灵敏度好,消耗有机溶剂少,实验耗时短、快速,适用于大批量快速检测,为研究葡萄酒中的有机磷农药残留提供了方法学基础。     

氨基功能化石墨烯固相微萃取-气相色谱法测定水样中7种有机磷农药残留量

目的建立氨基功能化石墨烯固相微萃取-气相色谱法同时测定水样中7种有机磷农药残留(硫线磷、地虫硫磷、氯唑磷、甲基毒死蜱、磷胺、喹硫磷和苯线磷)。方法水样中残留的有机磷农药用25 mg氨基功能化石墨烯富集,用6mL丙酮洗脱,然后使用气相色谱-火焰光度检测器(gas chromatography-flame photometric detector,GC-FPD)测定。对气相色谱条件和影响萃取效率的多种因素进行优化。结果在优化的条件下, 7种有机磷农药标准曲线线性关系良好,线性系数为0.9905～0.9988,检出限为0.025～0.04μg/L,定量限为0.08～0.12μg/L。氨基功能化石墨烯对7种有机磷农药的富集倍数为183倍～307倍,萃取率为45.8%～76.8%,3个浓度添加水平(1、5.0、50μg/L)的加标平均回收率在70.0%～105%,相对标准偏差为7.98%～14.5%。结论该方法具有操作简单,快速、准确度和灵敏度高、试剂用量少等特点,适用于水样中7种有机磷农药残留量的测定。     

固相分散萃取-气相色谱-质谱联用法测定葡萄酒中43种农药残留量

目的建立固相分散萃取结合气相色谱-质谱联用法(GC/MS)快速测定葡萄酒中敌敌畏、乐果、二嗪磷等葡萄种植过程中常用43种杀虫剂、杀螨剂及杀菌剂残留量。方法样品用乙腈快速提取、氯化钠和无水硫酸镁盐析后,经GCB粉、NH_2粉和PSA粉组合吸附剂净化,GC/MS外标法定性定量。结果43种农药在10~500μg/L范围内线性关系良好,相关系数R~2在0.9851~0.9997范围内,空白添加浓度在50~200μg/kg时,其回收率在67.43%~114.74%之间,相对标准差(n=6)小于13.6%,方法的测定下限(LOD)介于1~50μg/kg之间。结论本法简单、准确、快速,适合于葡萄酒中对43种农药残留量的检测。     

QuEChERS-气相色谱-三重四级杆质谱法检测石榴中的19种含磷农药残留

采用Qu ECh ERS前处理方法联合气相色谱串联三重四级杆质谱法(gas chromatography-triple quadrupole mass spectrometry,GC-MS/MS),建立了同时测定石榴中19种有机磷农药残留的分析方法。使用优化后的Qu ECh ERS方法对石榴进行前处理,选用乙酸乙酯为提取剂、N-丙基乙二胺(primary secondary amine sorbent,PSA)为净化剂,经Rtx-5MS色谱柱分离后在多反应监测模式(multiple reaction monitoring mode,MRM)下进行测定。结果表明:该方法在0. 01～1. 0 mg/L的线性范围内线性关系良好,相关系数(r)均大于0. 99,最低检出限(S/N=3)为0. 9～3. 7μg/kg,定量限(S/N=10)为3～12. 2μg/kg,加标回收率为73. 5%～120. 9%,相对标准偏差(RSD)为1. 1%～15. 7%。利用该方法对市售石榴进行有机磷农药进行检测,其中检出微量的久效磷和乐果2种农药。该方法快速、准确、灵敏度高,适用于石榴中有机磷农药的多残留检测。     

金属有机框架化合物ZIF-8基于QuEChERS-GC-MS/MS测定禽蛋中21种有机磷农药

基于改良QuEChERS前处理方法结合气相色谱-串联质谱(GC-MS/MS),建立了禽蛋中21种有机磷农药残留量的检测方法。样品经乙腈提取,金属有机框架材料-沸石咪唑酯骨架(ZIF-8)净化,用GC-MS/MS测定,采用HP-5ms柱进行分离,电子轰击离子源(EI)多反应监测模式(MRM)检测,以空白基质提取液匹配标准溶液外标法定量。结果表明：21种有机磷农药的仪器检出限(LOD)在0.1～5.6μg/kg之间,方法定量限(LOQ)在0.3～9.6μg/kg之间,相关系数(R²)均在0.9959以上;在10、20和40μg/kg 3个添加水平下,21种有机磷农药在禽蛋中的平均回收率在85.9%～118.0%之间,相对标准偏差在1.3%～5.2%之间(n=6)。该方法快速、操作简便、灵敏度高、准确,在禽蛋中有机磷农药残留检测中具有良好的应用前景。     

QuEChERS-气相色谱-三重四级杆串联质谱法高通量检测生鲜肉中有机磷农药残留

该研究旨在建立一种快速、有效检测生鲜肉中18种有机磷农药（organophosphorus pesticides, OPPs）残留的QuEChERS-GC-MS/MS检测方法。样品经饱和正己烷的乙腈溶液提取,MgSO₄、CH₃COONa、N-丙基乙二胺（N-propyl ethylenediamine, PSA）、十八烷基键合硅胶(C₁₈)分散固相萃取净化后,采用DB-1701色谱柱进行分离,GC-MS/MS检测。有机磷农药在1～100μg/kg线性关系良好,相关系数（R²）均>0.990 0,检出限为0.02～0.74μg/kg,定量限为0.08～2.48μg/kg,加标回收率为76%～106%,相对标准偏差为0.50%～7.9%。该实验建立的QuEChERS-GC-MS/MS方法可同时检测18种有机磷农药,操作简便、快速、灵敏、准确,能够满足生鲜畜禽肉中有机磷农药残留的高通量快速检测。     

QuEChERS-气相色谱法同时测定大米中10种有机磷农药残留量

目的建立一种QuEChERS前处理技术结合气相色谱法同时测定大米中10种有机磷农药(甲拌磷、地虫硫磷、除线磷、对氧磷、甲基嘧啶磷、地毒磷、异柳磷、杀扑磷、灭菌磷、乙硫磷)残留量的方法。方法样品经QuEChERS方法净化后浓缩,经Agilent HP-5色谱柱分离,以火焰光度检测器检测,峰面积外标法定量。结果 10种有机磷农药在0.050～1.0μg/mL范围内线性关系良好(r2不小于0.995);平均加标回收率为70.03%～104.20%,精密度为3.31%～10.44%(n=6)。方法检出限均小于0.12mg/kg。结论该法样品处理快捷,重复性、稳定性和灵敏度好,可用于大米中有机磷农残的检测。     

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.     

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.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.