乙酰丙酮分光光度法测定白菜中甲醛含量的方法优化及其在快检结果验证中的应用

目的建立乙酰丙酮分光光度法测定白菜中甲醛含量的方法,并用此方法验证甲醛速测盒的检测结果。方法以甲醛含量为指标,研究样品浸泡时间、加蒸馏水量、加磷酸量、蒸馏时间等前处理条件和显色时间、水浴时间、加乙酰丙酮量等测定条件对白菜中甲醛测定结果的影响。以大白菜为试样,对比乙酰丙酮分光光度法和甲醛速测盒的检测结果。结果白菜中甲醛含量测定的最佳的条件为样品浸泡时间35 min,加水量160 m L,磷酸添加量5 m L,蒸馏时间80 min,乙酰丙酮添加量1 m L,水浴时间5 min,显色时间15 min。在此条件下,白菜中甲醛回收率为95.2%～99.7%。甲醛速测盒的结果与之比对,结果一致。结论乙酰丙酮分光光度法结果准确,适合用于大白菜中甲醛的测定,实验中所用甲醛速测盒与之结果一致,可以快速有效测定白菜中甲醛含量。     

GDYQ-201SY型纺织品甲醛测定仪精度研究

通过用GDYQ-201SY纺织品甲醛测定仪测定一组已知浓度的甲醛标准溶液来检测该仪器的精密度与准确度，并与分光光度仪一起测试了某一纺织品中甲醛的含量，得出测定甲醛含量时甲醛测定仪的精密度和准确度随被测物甲醛含量的增大而趋于精确；与分光光度法测定甲醛含量测定结果之间无显著差异。     

褪色分光光度法测定面粉中的溴酸钾

用褪色分光光度法测定面粉中的溴酸钾的含量，该方法简便、快速，具有可操作性强、准确度高等特点，可以定量测定面粉中溴酸钾的含量。加标回收检测验证，其回收率在95％以上，相关系数0．9996，RSD〈5％。     

啤酒中的甲醛

我们对啤酒酿造过程的甲醛含量变化做了跟踪检测，现与大家共同探讨。 1甲醛检测方法 目前啤酒中微量甲醛的检测方法有两种：一种是农业部颁发的绿色食品中甲醛的检测方法，标准号为NY／T273-2002；另一个是发酵酒卫生标准规定的分析方法，即国标法。另外可采用高效液相色谱进行检测，但目前此方法还未列入国家标准中。我们分析采用的是国标法，其原理是甲醛在过量乙酸铵的存在下与乙酰丙酮和氨离子生成黄色的3．5．二乙酰基．1．4．二氢吡啶化合物，在波长415nm处有最大吸收，颜色的深浅与甲醛含量成正比，相应可得出试样中甲醛的含量。     

生物柴油中游离甲醇含量测定方法

介绍了一种测定生物柴油中游离甲醇的方法，它基于游离的甲醇被高锰酸钾氧化生成甲醛。甲醛与乙酰丙酮反应生成的衍生物在410nm处用紫外可见分光光度法测定。结果表明，甲醇在0-0．132mg／25mL范围内具有良好的线性关系俾=O．9967），回收率为95．05％-97．10％，精密度试验中相对标准偏差RSD值=0．522％（n=5）。此方法成本低，准确度高，重现性好，适于作为生物柴油中游离甲醇含量测试方法。     

测定甲醛含量也可不破损成衣

《丝绸》2008No。6上推荐了一种成衣无破损测定甲醛含量的方法。现有的国内外甲醛标准方法中，用于纺织品中甲醛含量检测则是采用水苹取法或者蒸汽吸收法，把甲醛从纺织品中分离出来，然后再用乙酰丙酮分光光度法测定。标准方法均为破坏性试验，即必须剪碎样品，破损纺织品，包括成衣制品。在进出口纺织品检测中，常常会碰到价格昂贵的高档进口成衣制品，没有多余的样品，     

成衣甲醛测试方法研究

现有的国内外甲醛标准方法中,纺织品甲醛含量检测是采用水萃取法或者蒸汽吸收法,把甲醛从纺织品中分离出来,然后再用乙酰丙酮分光光度法测定.标准方法均为破坏性试验.为了无破损地测定甲醛含量,在研究蒸汽吸收法原理的基础上,得出了一套成衣无破损测定甲醛含量的方法.     

EBT-1,2-丙二醇光度法测定食品中微量镁研究

建立了EBT-1，2-丙二醇水溶液光度法准确测定食品中镁含量的新方法。试样用HNOs-HClO4湿消化，并用钨酸钠消除Ca2＋、三乙醇胺．四乙烯五胺混合掩蔽剂掩蔽Te3＋、Al3＋等干扰离子后，在pH10．5的氨性缓冲溶液中，Mg2＋与EBT生成可溶于水的酒红色络合物，在分光光度计波长为520nm处测定其吸光度。测定结果的相对标准偏差小于1．0％，加标回收率在95．4％～102．4％之间。结果表明，改进后的方法操作简便、测定快捷、准确度高、干扰小，测定结果与国家标准方法相符，相对偏差小于2．0％。     

流动注射分析法测定啤酒中甲醛含量的研究

针对啤酒中甲醛检测方法操作烦琐，不适合在线检测的情况，建立了在线流动注射分光光度法直接测定啤酒中甲醛的方法。此方法快速，简便，精密度高，在0．2～10mg·L^-1范围内甲醛浓度与峰高成良好线性关系，相关系数r=0．9991，检出限为0．068mg／L，相对标准偏差（RSD）为0．67％，结果令人满意。     

微波消解-分光光度法测定肉制品中磷酸盐

为建立用微波消解技术进行样品前处理，磷钼蓝分光光度法测定肉制品中磷酸盐含量的方法；采用微波消解仪，在肉制品中加入硝酸密闭消解，消解液用磷钼蓝分光光度法在660hm波长处测定样品中磷的含量。结果是微波消解技术可将样品消解完全，采用磷钼蓝分光光度法测定体系中磷酸盐（以磷酸根计）的含量在0～150μg（25ml比色管）时，磷酸盐的含量与吸光度呈线性关系，相关系数0．9999；用本法测定了国家标准物质茶叶与小麦粉等，测定值与标准参考值基本一致，对实际样品的加标平均回收率在97．0％～105．5％之间。该法操作简单，试剂用量少、重现性好，用微波消解技术大大缩短了样品前处理时间，适于肉制品中磷酸盐含量的测定。     

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.     

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.