纸质食品接触材料中多环芳烃的检测方法比较

分别采用索氏萃取法、微波萃取法和超声萃取法提取纸质食品接触材料中的多环芳烃(PAH s),对三种方法的提取效果进行了比较,发现超声萃取法的综合性能最佳。对萃取物分别进行气相色谱/质谱-选择离子监测法、气相色谱/串联质谱法和超高效液相色谱法分析,建立了三种测试方法,并对方法的线性关系、精密度、检出限等参数进行了比较。分别采用这三种方法对市售纸质食品接触材料中的PAHs含量进行测定,发现这三种测试方法所得结果之间不存在显著性差异。     

纸质食品接触材料的多环芳烃气相色谱/质谱-选择离子监测法测定

建立了一个气相色谱/质谱-选择离子监测方法,对纸质食品接触材料中18种禁用多环芳烃进行了同时测定,该方法以正己烷/丙酮(1∶1)为提取溶剂,40℃下超声提取纸质食品接触材料中的多环芳烃,提取产物经硅胶固相萃取柱净化后进行气相色谱/质谱-选择离子监测法测定,外标法定量。在S/N=3的条件下,各目标化合物的检出限为0.1~1.0μg/kg。方法的加标平均回收率为55.98~95.62%,相对标准偏差为2.87~6.98%,线性相关系数均大于0.997。该方法快速简便,定性准确,检出限低,可完全满足多环芳烃检测的技术要求,可用于食品接触材料中18种禁用多环芳烃的同时测定。采用该方法对市售食品接触材料进行测试,结果在米黄色再生包装纸袋中检出高含量的菲。     

纸质食品接触材料中18种禁用多环芳烃的快速测定

以正己烷／丙酮（1：1,V／V）为萃取溶剂,40℃下超声萃取纸质食品接触材料中的多环芳烃（PAHs）,提取产物经硅胶固相萃取柱净化后进行超高效液相色谱分析,外标法定量,从而建立了一个同时测定纸质食品接触材料中18种禁用多环芳烃的高效液相色谱方法。在信噪比（S／N）=3的条件下．各目标化合物的检出限为0．02～0．10mg／kg,其线性相关系数,均不低于0．9999。各组分的平均加标回收率为58．13％～95．86％,相对标准偏差（RSD）为1．58％～4．68％。应用该方法对市售纸质食品接触材料中的多环芳烃含量进行测定,结果在一个样品中检出高浓度的菲。该方法简便快速、灵敏度高、定性定量准确,可满足多环芳烃检测的技术要求,适用于纸质食品接触材料中多环芳烃的测定。     

GC-MS测定纺织品中多环芳烃

以甲苯为萃取溶剂,采用加速溶剂萃取方法,以外标法定量,建立了一种测定纺织品中多环芳烃(PAHs)含量的气相色谱-质谱联用法。该方法检出限为50μg/kg,工作曲线线性范围为5~500μg/L,加标回收率为86.5%~105%,相对标准偏差为1.0%~4.8%。检测结果表明,该方法简便可靠,能够达到纺织品材料中16种多环芳烃的检测需求。     

气相色谱-质谱法测定食用槟榔中多环芳烃

建立了测定食用槟榔中15种多环芳烃(PAHs)的气相色谱-质谱(GC-MS)的方法。样品经正己烷超声萃取后,采用凝胶渗透色谱(GPC)和分散固相萃取(DSPE)进行净化,用气相色谱-质谱(GC-MS)测定。在优化条件下,采用外标法测定,被测目标在线性范围内其相关系数(r2)不低于0.996,检出限为0.2 ng/m L~1.0 ng/m L;精密度(RSD,n=7)不大于4.38%,回收率试验结果满意。该方法用于食用槟榔中多环芳烃的测定是可行的。     

改进QuEChERS-气相色谱-质谱法快速分析蜂花粉中的多环芳烃

建立了蜂花粉中16种多环芳烃(PAHs)的QuEChERS快速提取、净化方法及气相色谱-质谱检测方法。蜂花粉样品经水溶解后在无缓冲体系下用乙腈萃取目标化合物,选择150 mg PSA/150 mg C18/900 mg Mg SO4/500 mg Florisil组合填料进行净化,之后,用GC-MS测定。在最优化色谱条件下,16种PAHs呈现良好的线性关系,方法检出限为0.2~3.3 ng/g,定量限为0.7~11.0 ng/g。大部分PAHs的回收率在61.0%~135.4%之间,相对标准偏差小于11.8%。改进的QuEChERS-GC/MS方法成功应用于蜂花粉(采自不同污染程度地区)PAHs的测定,结果显示不同花粉样品中PAHs种类和含量存在明显差异。本研究为蜂花粉的质量安全评价以及进一步开展蜂花粉与环境污染物之间相关性研究奠定了基础。     

气相色谱-质谱法测定醇食品模拟物中 16种多环芳烃

目的 建立固相微萃取-气相色谱-质谱联用仪测定醇食品模拟液中16种多环芳烃的分析方法。方法 优化了萃取方式、萃取温度、萃取时间、解吸时间和振荡速率等萃取条件, 样品采用气相色谱-质谱联用仪(gas chromatography-mass spectrometry, GC-MS)总离子流和选择离子模式进行定性定量测定。结果 16种多环芳烃在0.01~10 ?g/L范围内线性良好, R2大于0.99。在0.1、0.5、1.0 μg/L 3个添加水平下, 16种多环芳烃的平均回收率为76.52%?119.8%, 相对标准偏差为0.99%?15.93%。结论 该方法操作简便、灵敏度高、准确度好, 能够满足醇食品模拟物中多环芳烃化合物的检测要求。     

固相萃取-气相色谱-串联质谱法测定蔬菜中的 16种多环芳烃

目的建立固相萃取-气相色谱-串联质谱法测定蔬菜中16种多环芳烃(polycyclic aromatic hydrocarbons,PAHs)的分析方法。方法样品经正己烷-二氯甲烷匀浆提取,经中性硅胶-中性氧化铝复合固相萃取柱净化后,用多反应监测(multiple-reaction monitoring,MRM)正离子扫描方式进行检测,气相色谱-串联质谱法测定,内标法定量。结果 16种目标物在2~250 ng/m L范围内呈线性关系良好,方法的检出限(S/N=3)为0.09~0.51μg/kg,定量限(S/N=10)为0.31~1.68μg/kg。在2、5、20μg/kg 3个加标水平下的平均回收率为添加平均回收率范围为70.6%~109.2%,相对标准偏差(RSD)为1.95%~10.4%。结论该方法选择性好、抗干扰能力强,能满足国内外法规的要求,可用于蔬菜中多环芳烃残留的日常检测。     

微波萃取-GC/MS-MS测定乙二醇醚类有机溶剂

建立了气相色谱/串联质谱方法,测定纺织品中残留的15种乙二醇醚类有机溶剂。该方法以乙醇为萃取溶剂,100℃下微波萃取纺织品中残留的乙二醇醚类有机溶剂,萃取液直接进行气相色谱/串联质谱分析,外标法定量。在信噪比(S/N)为10的条件下,各组分的定量下限为5~20 mg/kg。在三个加标水平下,平均回收率为81.7%~94.5%,相对标准偏差为2.1%~6.8%。该方法简单快速,可满足纺织品中乙二醇醚类有机溶剂残留量检测的技术要求。     

高分子印迹固相萃取法测定熏烤肉制品中16 种欧盟优控多环芳烃

目的 建立高分子印记固相萃取-气相色谱质谱联用(MIPSPE-GC/MS)测定熏烤肉中 16 种欧盟优控多 环芳烃的检测方法。方法 样品经均质、超声波提取、高分子印记固相萃取柱净化后, 采用气相色谱质谱联用 仪在选择离子(SIM)扫描模式下进行测定, 内标法定量。 结果 本方法检出限为 0.07~0.24 μg/kg, 在 1~500 μg/L 范围内目标化合物具有很好的相关性, 相关系数均大于 0.999。日内及日间精密度小于 10%, 在 1、5 μg/kg 两 个加标水平下, 16 种 PAHs 回收率为 66.27 % ~ 111.61%, 相对标准偏差均小于 10%。 结论 本方法灵敏、 快速、 简便, 能满足熏烤肉制品中欧盟多环芳烃的检测要求。     

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.