分散固相萃取法快速测定大米中的酰胺类除草剂

利用分散固相萃取-质谱法测定了大米中的6种酰胺类除草剂,比较了分别用乙酸乙酯和乙腈溶液作为提取溶剂对目标提取物的提取效率,并对样品的前处理方法和净化条件进行优化.结果表明:大米经乙酸乙酯提取后,用PSA分散净化后,6种酰胺类除草剂在0.02～0.5 mg/L范围内具有良好的线性,样品的添加回收率为80.5%～111.7%,相对标准偏差为2.1%～10.7%,最低检出限为1.28～3.50μg/kg.该方法操作简便、经济、快速,适用大批量样品的分析.     

气相色谱法测定玉米中莠去津及6种酰胺类除草剂残留量

研究利用气相色谱法同时测定玉米中莠去津及6种酰胺类除草剂残留量的方法。首先采用乙酸乙酯+环己烷萃取出玉米中残留的莠去津及6种酰胺类除草剂,再使用弗罗里矽柱净化,经浓缩定容后的样液用气相色谱仪进行分离检测,最终实现定性和定量测定。试验结果表明,该方法最低检出限可达0.003μg/ml,回收率为88.0%~106.0%,相对标准偏差为3.4%~6.9%。该方法操作简便、快捷,并具有较高的灵敏度和准确度,能实现对玉米中莠去津及6种酰胺类除草剂残留的定性与定量分析。     

气相色谱-质谱法同时测定草莓中7种除草剂农药残留

建立了气相色谱-质谱法(GC-MS),选择离子技术对草莓中乙草胺、西玛津、哒螨酮、禾草克、阿特拉津、扑草净、甲草胺多残留进行同时检测的方法.匀浆后的草莓试样用乙酸乙酯进行提取,提取液经滤纸过滤后收集,再浓缩蒸干,用丙酮:正己烷(30:70,V/V)溶液溶解至5ml,经Florisil固相萃取柱净化,吹干后用丙酮定容,供气相色谱-质谱联用仪进行测定.实验结果表明,除草剂在0.05～1.00 μg/ml浓度范围内,具有良好的线性响应,相关系数分别在0.9964到0.9998之间,添加浓度为0.05～1.00 μg/ml时,回收率在77.4%～125.2%之间,该方法的最低检测限为0.01 μg/g.     

GC-ECD法测定纺织助剂中五氯苯酚含量

采用气相色谱-电子俘获检测器法(GC-ECD),测定及验证纺织品中五氯苯酚的含量。用水蒸气蒸馏提取试样,提取液经乙酸酐乙酰化后以正己烷提取,用气相色谱-电子俘获检测器(GC-ECD)测定,外标法定量。通过优化,本方法平均回收率为88.2%～102.1%,精密度为8.0%~9.2%,方法测定低限为10μg/kg。各项指标均满足有关要求。     

气相色谱法同时测定水果中氯草定、恶草酮、莠去津3种除草剂残留

建立了气相色谱法检测水果中氯草定、恶草酮、莠去津3种除草剂残留的快速测定方法.采用二氯甲烷提取样品中农药,并用弗罗里硅土的层析柱净化,二氯甲烷:丙酮混合液(9:1)洗脱.气相色谱附电子捕获检测器(ECD)检测,用保留时间定性、外标法定量.结果表明,3种除草剂的添加回收率在82.8%～102.5%之间,变异系数在0.5%～6.4%之间,最低检出限为0.001～0.021μg/g.     

QuEChERS-气相色谱/质谱法检测香椿等芽菜类蔬菜中5种酰胺类杀菌剂残留量

目的建立QuEChERS-气相色谱-质谱法定量检测芽菜类蔬菜中的5种酰胺类杀菌剂的含量的分析方法。方法芽菜类蔬菜加乙腈溶剂均质后, QuEChERS提取法进行提取、净化,提取液氮吹至近干,加正己烷溶解、定容至1 mL,气相色谱-质谱仪定量检测。结果乙草胺、甲草胺、灭锈胺、苯酰菌胺和啶酰菌胺浓度在0.02～10.0μg/mL之间,线性关系良好,相关系数(r~2)均大于0.995;检出限分别为0.007、0.006、0.004、0.003、0.003 mg/kg;加标回收率在84.6%～105.2%之间;重复性RSD(n=6)在5.0%以内。结论该方法具有操作简便、回收率好等优点,适用于芽菜类蔬菜中酰胺类杀菌剂的检测。     

纺织品中有机氯农药残留量检测方法研究

将纺织品试样经丙酮-正己烷（1＋8）超声波提取，提取液浓缩定容后，用配有电子俘获检测器的气相色谱仪（GC-ECD）测定，外标法定量，或用气相色谱-质谱（GC-MS）测定，外标法定量，采用选择离子检测进行阳性确证。为检测纺织品中有机氯农药残留量提供了2种测试方法，可供不同条件的实验室选择。研究结果表明，2种方法的回收率、相对标准偏差以及测定低限均能满足检测需要。     

QuEChERS-气相色谱-质谱法测定大米中的10种酰胺类除草剂残留量

目的建立一种QuEChERS结合气相色谱-质谱法同时测定大米中10种酰胺类除草剂农药(甲草胺、乙草胺、丙草胺、丁草胺、异丙甲草胺、氟酰胺、二甲戊乐灵、灭锈胺、吡氟酰草胺和苯噻酰草胺)残留的分析方法。方法样品经乙腈提取,QuEChERS方法净化浓缩后,以气相色谱-质谱法采用选择离子监测模式进行分析,用灵敏度最高的离子对定量。结果在0.05~0.5 mg/L范围内,10种除草剂农药线性关系良好,线性相关系数(r~2)不小于0.99,方法检出限均小于9μg/kg。在0.05、0.2和0.5 mg/L 3个添加水平下,平均加标回收率为82.9%~107.9%,相对标准偏差为1.2%~5.7%(n=6)。结论该法具有前处理快速简单、精密度好、灵敏度高等优点,适用于大米中酰胺类除草剂农残的快速验证和定量检验。     

正已烷萃取法测定进口水果中六六六、滴滴涕

采用气相色谱法（带有电子捕获检测器ECD），以正已烷、丙酮为提取溶剂，用浓硫酸磺化法净化提取液，对进口水果中的六六六、滴滴涕各4种异构体农药进行了多残留检测。结果表明：以正己烷与丙酮的混合提取剂的提取效果好，其平均回收率范围为93．7％-122．7％，相对标准偏差分别为1％-6％，在程序升温的条件下，8种农药可很好地分离，检出限范围为0．0006—0．006mg／kg，准确度和精确度均达到了进口水果中六六六、滴滴涕农药残留分析的要求。     

气相色谱-质谱法测定纺织品中6种苯氧羧酸类农药残留量

为测定纺织品中6种苯氧羧酸类农药残留量，采用酸性丙酮水溶液提取试样，提取液经二氯甲烷液-液分配提取后，再用甲醇-三氟化硼乙醚溶液甲酯化，经正己烷提取，用配有质量选择检测器的气相色谱仪（GC／MSD）测定。经前处理条件试验，气相色谱-质谱条件选择试验，气相色谱／质谱阳性确证条件试验，回收率、精密度和测定低限技术指标均完全满足检测需要。     

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.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.