四-（对甲基苯基）-卟啉柱前衍生，高效液柱色谱法测定食品中痕量铅、镉、汞

研究了用四-(对甲基苯基)-卟啉柱前衍生，高效液相色谱法测定食品中痕量铅、镉、汞的方法。食品样品用湿法消化后，消化液中的铅、镉、汞用四-(对甲基苯基)-卟啉(T4MPP)柱前衍生，然后用甲醇(内含0．01mol／L四氢吡咯-醋酸缓冲盐)和四氢呋喃(内含0．01mol／L四氢吡咯-醋酸缓冲盐)为流动相梯度洗脱，Waters Xterra^TMRP18(3．9150mm，5μm)色谱柱为固定相分离铅、镉、汞的T4MPP络合物，用二极管矩阵检测器检测，铅、镉、汞含量在0．01～3mg／L范围内与峰面积成线性关系，根据信噪比(S／N=3)，方法检测限为：铅2．3μg／L、镉1．8μg／L和汞2.5μg／L，方法相对标准偏差为2．1％～3．5％，标准回收率为93％～106％，该方法用于测定食品中的铅、镉、汞，结果令人满意。     

微波消解电感耦合等离子体发射光谱法同时测定水产品中铅镉铬汞砷硒有害元素的研究

研究了微波消解样品，试液用ICP－AES法同时测定样品中铅、镉、铬 、汞、砷、硒的新方法。在选定的最佳条件下测铅、镉、铬、汞、砷、硒的检出限分别为0.0008、0.0007、0.0018、0.0028、0.0012、0.0046μg/L，回收率为94．5％－104．2％，RSD为1．4％－2．6％。本法准确、快速、简便，应用于水产品的测定结果满意。     

微波消解-原子荧光光谱法测定饮料中镉

目的：建立原子荧光光谱法测定果汁饮料中镉的检测方法。方法：采用微波消解法消解果汁饮料样品后，用原子荧光光谱法测定其中的痕量镉的含量，对测定条件进行了优化，并对测定方法进行了方法学考察。结果：镉的校准曲线的相关系数r=0．9995，线形范围为0-60．0μg／L，检出线为0．0472μg／L，回收率为94．9％-100．5％，RSD为5％。结论：该方法快速、简便、准确且灵敏度高，为果汁饮料中镉含量的测定提供了较好的方法，用本方法测定标准样品达到满意效果。     

冷蒸气发生-原子吸收光谱法测定纺织品中可萃取痕量镉

本文建立了以酸性人工汗液提取，冷蒸气发生-原子吸收光谱法测定纺织品中可萃取痕量镉的方法。研究了载气流速、还原剂的选择、增敏剂加入量、介质酸度以及共存离子的干扰等因素。在试验选定的最佳条件下，镉浓度在0．05μg／L～40．0μg／L呈良好线性关系，相关系数≥0．9993，方法检出限为0．020μg／L，样品加标回收率为90．8％～106．1％，相对标准偏差小于3．8％。该方法灵敏度高、操作简单、干扰小，用于纺织品中可萃取痕量镉测定，结果满意。     

胶体钯基体改进剂石墨炉原子吸收光谱法测定食盐中铅、镉

建立了胶体钯基体改进剂用于石墨炉原子吸收光谱法测定食盐中铅、镉的方法。方法采用食盐直接溶解后,以胶体钯作为基体改进剂,石墨炉原子吸收光谱法直接测定。在铅浓度为0~40μg/L、镉浓度为0~4μg/L的相关系数均0.999,铅的检出限为0.3μg/L,样品加标回收率为95.2~101.8%;镉的检出限为0.1μg/L,样品加标回收率为91.0~103.3%,相对标准偏差均5%。该方法准确、灵敏、简便,满足食盐中铅、镉的测定。     

端视ICP-AES测定蜂产品中重金属有害元素残留

采用微波消解-端视等离子体发射光谱（ICP—AES）测定蜂产品中重金属微量元素铅、镉、砷，并对ICP—AES工作参数及条件进行了优化和选择，Pb、cd、As的检出限分别为2．9×10^-3mg／L、0．056×10^-3mg／L、5．2×10^-3mg／L，线性范围为0-500μg/L，相对标准偏差范围为2．9％-8．5％；回收率范围为91％-102％。该方法与国标法比较，结果无显著性差异，能满足蜂产品测定要求。     

差分脉冲溶出伏安法检测海产品中重金属的方法学研究

建立了微波消解-差分脉冲溶出伏安法测定海产品中5种重金属的方法。采用微波消解法对样品进行消解,调节样品至中性,利用LK-4600水质重金属检测仪,采用差分脉冲溶出伏安法对样品进行测定,结果表明该方法的线性关系良好,5种重金属的相关系数r均大于0.995;检出浓度分别为铅0.1μg/L,镉0.05μg/L,铬10.0μg/L,汞5.0μg/L,砷5.0μg/L,以称样量0.5 g计,方法检出浓度分别为铅0.3μg/L,镉0.12μg/L,铬8.9μg/L,汞4.2μg/L,砷6.4μg/L;加标回收率均在90%~110%之间。     

标准加入法-抗坏血酸基体改进剂GFAAS测定腐乳中痕量铅

建立腐乳中痕量铅GFAAS测定方法。采用抗坏血酸为基体改进剂降低铅的原子化温度，分析元素在大量样品基体挥发前完成原子化；应用标准加入法，测量值在相同干扰情况下获得，两者结合能有效消除GFAAS测定腐乳中铅存在的大量样品基体干扰，使测定结果准确可靠。本方法检出限为0．05mg／kg，精密度2．3％～10．69／5，在5μg／L、10μg／L添加水平回收率为88．29／6～1169／6、97．89／5～120％。     

流动注射分光光度法测定海水中痕量的镉

建立了在Cd（Ⅱ）-碘化钾-乙基紫高灵敏度显色体系下，采用流动注射分析技术测定海水中痕量镉的新方法，并确定了该方法的最佳条件。线性范围为0．5～12μg／L，相对标准偏差RSD为1.21％（n=11，CCd（Ⅱ）=10μg／L），检出限为0．1μg／L。     

动力学光度法测定食品中痕量亚硝酸根

基于稀H3PO4介质中，痕量亚硝酸根对高碘酸钾氧化结晶紫的褪色反应有明显的催化作用，建立了痕量亚硝酸根的动力学光度测定法，方法检出限为0．06μg／L，线性范围为0～4．0μg／L。用于测定食品中的痕量亚硝酸根，结果与Griess法相符，6次测定结果的RSD≤5．0％。     

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