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。     

分散固相萃取-气相色谱-串联质谱法同时测定草莓及土壤中5种杀菌剂

目的 建立分散固相萃取-气相色谱-串联质谱分析法同时检测5种不同类型杀菌剂(五氯硝基苯、百菌清、氟吡菌酰胺、肟菌酯、咪鲜胺)的含量。方法 样品经10 mL乙酸乙酯提取, N-丙基乙二胺与C18(50 mg: 50 mg)分散固相萃取混合净化。采用多反应监测模式进行定性, 外标法进行定量分析。结果 5种杀菌剂在1~1000 μg/L浓度范围内呈线性, 相关系数为0.9802~0.9996。空白样品在10、100和200 μg/kg添加浓度下的回收率为84%~119%, 相对标准偏差为1%~17%(n=3), 方法定量限为最小添加浓度10 μg/kg。结论 该方法能够满足土壤和草莓样品中痕量杀菌剂检测的要求。     

优化气相色谱-质谱法测定水果和蔬菜中五氯硝基苯残留量的前处理方法

目的建立检测水果和蔬菜中五氯硝基苯残留量的气相色谱-质谱联用方法。方法样品采用3种不同前处理法进行提取净化后,采用内标法进行定量。优化样品预处理方法,选择适宜的提取溶剂、最佳的超声和振荡时间,采用选择性离子扫描模式进行质谱检测。结论在0.02~0.10μg/m L添加水平,经正己烷提取和Qu ECh ERS柱净化处理的样品,其五氯硝基苯的平均回收率在68.32%~96.82%之间,相对标准偏差为3.4%~5.9%(n=6)。以信噪比S/N=3计算五氯硝基苯的最低检出限为0.002 mg/kg,方法的定量限为0.0067 mg/kg(S/N=10)。结论优化后的前处理方法结果准确、重现性好,检出限相对较低,满足水果和蔬菜中五氯硝基苯残留量的检测要求。     

固相萃取-GC-ECD检测沃柑中的腐霉利、五氯硝基苯和甲氰菊酯残留

目的:实验开发固相萃取-GC-ECD检测沃柑中的腐霉利、五氯硝基苯和甲氰菊酯残留的分析方法。方法:沃柑样品粉碎后,准确称取10.0 g,置塑料离心管中,加20 mL乙腈提取,Florisil固相萃取柱净化、富集,正己烷洗脱,洗脱液氮吹至近干,残渣加1.0 mL正己烷溶解,0.45μm滤膜滤过,上气相色谱仪,外标法定量检测。结果:腐霉利、五氯硝基苯和甲氰菊酯在浓度范围为0.02～10.0μg/mL内,线性关系良好;检出限分别为:0.004 mg/kg、0.008 mg/kg和0.004 mg/kg;加标回收率在87.4～105.3%之间;重复性良好。结论:实验证明,此方法快速、准确,适用于沃柑等水果中农药杀虫剂残留的检测。     

高效液相色谱法检测蔬菜中百菌清及其代谢产物的方法研究

建立了同时检测蔬菜中百菌清(CHT)及其代谢产物(4-羟基百菌清,CHT-OH)残留的高效液相色谱分析法。样品经丙酮提取,弗洛里硅土柱净化浓缩后以适量甲醇定容,HPLC紫外检测器检测,以C18色谱柱分离,甲醇∶水(90∶10,V/V)为流动相,流速为0.7mL/min,检测波长240nm。结果表明,百菌清、4-羟基百菌清的检测线性范围分别为0.05～10mg/kg和0.01～10mg/kg,相关系数r=0.9999。方法检出限分别为0.012mg/kg和0.005mg/kg,二者的平均加标回收率为83.5%～121.3%,RSD为2.4%～4.6%,该方法可用于市售蔬菜样品的测定。     

固相萃取-高效液相色谱-质谱法检测大豆中氯嘧磺隆除草剂的残留量

实验建立了固相萃取-高效液相色谱-质谱分析检测方法,对大豆中氯嘧磺隆除草剂的残留量进行了研究。样品经甲醇-超声波提取、正己烷液-液分配、固相萃取柱净化,将处理好的样品进行液相色谱定量分析、采用液相色谱-质谱进行定性检测。实验结果表明:氯嘧磺隆在0.1～200.0mg/L范围内浓度与峰面积具有良好的线性关系,相关系数为0.9997(n=3);在2.0～100.0μg/kg范围内,加标回收率为92.6%～95.2%;RSD为1.27%～2.64%;最低检测限为10.0μg/kg(S/N=3)。本方法具有简便、快速、准确、净化效果好等特点,适用于大豆中氯嘧磺隆除草剂的残留分析检测。     

DSPE-LC-MS/MS法测定海红果中9种杀菌剂残留量

建立分散固相萃取(DSPE)-液相色谱-质谱法(LC-MS/MS)测定海红果中9种杀菌剂(嘧霉胺、百菌清、稻丰散、甲霜灵、三唑酮、五氯硝基苯、烯酰吗啉、咪鲜胺、苯醚甲环唑)残留量的检测方法。样品匀浆粉碎后经乙腈提取、氧化铝萃取剂净化后,采用Atlantis T3色谱柱分离,LC-MS/MS测定。结果表明:9种杀菌剂在5.0μg/L~500μg/L范围内,呈良好的线性关系,线性相关系数R~2≥0.999 3;检出限为0.03μg/kg~1.0μg/kg,定量限为0.1μg/kg~3.0μg/kg;回收率在80.4%~102.3%,相对标准偏差(RSD)在1.1%~5.8%之间。     

果蔬中二甲戊乐灵、氟乐灵、双丁乐灵残留测定

采用基质分散固相萃取(MSPD)为样品前处理方法,建立气相色谱-串联四极杆质谱快速检测蔬菜、水果中二甲戊乐灵、氟乐灵、双丁乐灵残留分析方法。果蔬类样品经乙腈提取,乙二胺-N-丙级甲烷(PSA)分散固相(DSPE)净化后,应用气相色谱/四级杆质谱仪多离子反应监测(MRM)定量检测。结果表明,在0.005 mg/kg～0.2 mg/kg添加水平内二甲戊乐灵、氟乐灵、双丁乐灵的平均添加回收率在78.5%～109.3%之间,相对标准偏差不大于8.8%。     

固相萃取-高效液相色谱法测定蔬菜中三唑酮、 百菌清和乙烯菌核利残留量

目的建立固相萃取-高效液相色谱-二极管阵列检测法测定蔬菜中三唑酮、百菌清和乙烯菌核利残留量的方法。方法蔬菜样品用乙腈超声提取,加入氯化钠进行盐析脱水,提取液过中性氧化铝柱净化,用正己烷/丙酮(90:10,V:V)淋洗液洗脱,洗脱液水浴氮吹近干,流动相定容后采用高效液相色谱法进行测定,外标法定量。结果三唑酮、百菌清和乙烯菌核利质量浓度在0.02~5.0 mg/L范围内与其峰面积呈良好的线性关系,方法检出限为0.02 mg/kg,加标回收率为89.5%~105.1%,精密度(relative standard deviation,RSD)为0.85%~4.25%。结论该方法操作简单、准确,可应用于蔬菜中三唑酮、百菌清和乙烯菌核利的检测。     

果蔬中6种杀真菌剂残留的固相分散气相色谱检测及基质效应

采用基质固相分散样品前处理技术,气相色谱-电子捕获检测器测定果蔬中残留的常用杀真菌剂--五氯硝基苯(PCNB)、五氯苯胺(PCA)、甲基五氯苯基硫醚(MPCS)、腐霉利(PRO)、克菌丹(CAP)和异菌脲(IPR)。对影响提取效果的参数,如吸附剂类型、提取溶剂、超声波辅助提取等工艺条件进行优化。利用空白基质配制标准样品溶液来补偿和消除色谱分析中存在的基质效应,结果表明,该方法的回收率在78.4%～109.7%,相对标准偏差低于10%,检测限0.1～0.4μg/kg。该方法可用于水果、蔬菜中杀真菌剂残留量的测定。     

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.     

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.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status