IC-ICPMS联用技术在膨化食品溴形态分析中的确证检测

建立了膨化食品中溴形态的离子色谱(ICS)和电感耦合等离子体质谱(ICP-MS)联用分析确证技术。以水超声波提取溴酸盐及溴化物,用C18固相萃取小柱净化和0.22μm水相滤膜过滤,以IonPac AS19(250 mm×4 mm)阴离子色谱柱分离溴形态,在线自动生成35 mmoL/LKOH淋洗液,流速1.0 mL/min;进样体积25μL,ICS-ICP-MS测定。在10～50μg/L范围内呈现良好的线性关系,溴酸盐检出限为0.019 mg/kg,溴化物检出限为0.182 mg/kg,方法回收率82.6%～114.4%,精密度2.1%～10.5%。结果表明,该方法快速、简便,灵敏度高,干扰少,适用于检测基体复杂的膨化食品中痕量的溴酸钾含量,克服了采用GB/T20188-2006离子色谱法检测膨化食品中溴酸盐含量时可能存在的假阳性,为食品中溴酸盐检测提供了一种可靠、科学和准确的确证方法。     

活性炭的筛选及其吸附饮用水中低量溴化物的研究

本文通过研究星光K02活性炭、星光K04活性炭和太西活性炭等六种活性炭对饮用水中低量溴化物的吸附效率,筛选出了吸附效果最佳的太西活性炭。同时探讨了不同的活化方式、不同的吸附时间以及饮用水中不同的p H值对TAC(太西活性炭)吸附饮用水中低量溴化物(7.50μg/L)效率的影响。实验采用了蒸馏水浸泡和稀盐酸浸泡两种活化方式,用CO_2酸化的方式将饮用水中pH值分别调至6.00、7.00和7.68三个水平,在不同的时间点取样,用离子色谱仪检测其溴化物含量。不同条件下,TAC吸附溴化物效率不同。实验结果表明,用稀盐酸浸泡作为活化方式,同时将饮用水的p H值调至6.00,在实验开始后的两个小时内TAC吸附溴化物效果最佳,能达到85.35%,此时溴化物含量为1.10μg/L,即使在后续的臭氧灭菌阶段,溴离子全部被氧化成溴酸盐,溴酸盐的值会在5μg/L以内,远小于GB 5749-2006和GB 8537-2018中溴酸盐的规定限值(10μg/L),同时,TAC对饮用水中的常量元素钾钠钙镁、微量元素锶及偏硅酸等影响不大(小于10%)。因此,在实际生产中,可先将饮用水中p H值调至6.00,然后采用盐酸溶液预处理后的TAC对饮用水中低量溴离子进行去除。     

矿泉水臭氧消毒中溴酸盐的形成与控制

为控制矿泉水中溴酸盐含量,采用改变臭氧浓度的方法,对添加溴离子的矿泉水、超纯水和自来水分别进行臭氧氧化5 min,观察臭氧氧化过程中臭氧、溴离子以及水质对溴酸盐生成的影响;同时利用向自来水中添加一定浓度溴离子的方法,研究CT值(Ozone Concentration×Contact Time,CT)对溴酸盐生成的影响。结果表明,随着臭氧浓度和溴离子浓度的增加,溴酸盐生成量增加。当臭氧质量浓度≥0.4 mg/L,添加相同浓度的溴离子时,矿泉水中生成的溴酸盐量大于自来水和超纯水中溴酸盐量。矿泉水不同,添加相同浓度的溴离子,生成的溴酸盐量也不同,但当臭氧质量浓度≥0.4 mg/L时,溴酸盐量均大于10μg/L。CT值增大导致溴酸盐生成量大幅增加。因此,可以通过降低臭氧浓度和溴离子浓度的方法,减少臭氧消毒中溴酸盐的生成量。     

ICP-MS法测定食品、食品添加剂及食品包装材料中重金属元素的研究进展

电感耦合等离子体质谱法（ICP-MS）是检测痕量重金属最有效的方法之一,其所具备的灵敏度高、线性范围广、检出限低、多元素同时检测等优点,使其广泛应用于复杂基质中重金属含量的检测。该文综述了近年来ICP-MS在食品基质中重金属含量测定方面的应用现状,对其检测原理、运行参数及应用领域等进行了总结,同时还展望了ICP-MS在食品、食品添加剂及食品包装材料中重金属检测的发展趋势,以期为ICP-MS技术在食品重金属检测领域更广泛的应用提供参考,同时为保障食品安全提供技术借鉴。     

溴酸盐在食品及饮用水中的危害及检测

溴酸盐是一种禁用食品添加剂,具有致癌性。溴酸盐滥用及超标事件在市场上依然存在,影响食品安全,有效控制及禁止滥用尤为重要。同时应做好市场监测,建立有效的检测手段,保证食品安全。     

包装饮用水中溴酸盐检测经济解决方案

近日．国家卫生计生委办公厅下发了《包装饮用水》、辐射食品等14项食品安全国家标准（征求意见稿）．其中《包装饮用水》国标中新增溴酸盐指标。目前在纯净水生产中．臭氧消毒因副产物的危害性小,成本较低而被广泛应用。然而,使用臭氧对纯净水消毒的过程中,会将水体中自然存在的溴化物氧化为对人体有害的溴酸盐．而溴酸盐则是被国际癌症研究机构定为2B级的潜在致癌物。虽然溴酸盐含量短期内不会对饮用者的身体健康造成任何危害,但是长期饮用这种高溴酸盐含量的饮品．将增加癌症的患病率,过量食用溴酸盐会损害人的血液、中枢神经和肾脏等。     

液体有机溴化物溴含量的分析方法

本文针对利用氧瓶燃烧法测定液体有机溴化物中溴含量结果偏低的缺点 ,对实验方法进行了改进 ,提出了测定液体有机溴化物中溴含量较理想的方法     

矿泉水中溴酸盐的形成与控制

<正>正常情况下,自然界的矿泉水中溴酸盐的含量几乎为零,但是因其富含矿物离子的原因,溴离子(Br-)却是普遍都含有。在使用臭氧对含有溴化物的矿泉水进行杀菌消毒时,溴化物容易与臭氧发生反应,被氧化成为溴酸盐,并以Br03-的形式存在于水中。由于国家饮用水标准对菌落数量的要求非常严格,不少饮用水厂家采用O3对其水产品开展杀菌消毒的工作以降低菌落数量,由此也就顺理成章     

丙烯酸树脂中游离单体含量测定方法的改进

一、概述用溴化法测定丙烯酸树脂乳液中游离单体已有几十年的历史,也是我国丙烯酸树脂行业多年来一直采用的方法。其原理是以溴化物—溴酸盐测定单体中的双键为基础,溴酸钾在氧化溴化氢时所析出的溴能迅速地在     

高压脉冲电场杀菌技术降低水中溴酸盐含量的研究

目的：寻找能够替代臭氧杀菌的新技术,以降低水中溴酸盐含量。方法：采用高压脉冲电场(pusled electricfield,PEF)杀菌技术,用靛蓝二磺酸钠分光光度法测定臭氧浓度,用离子色谱法测定溴酸盐的浓度。结果：PEF对水中常见微生物至少达到了5.5 个对数级降低的杀灭效果;含有0.54mg/L 溴离子质量浓度的水中分别加1.769mg/L、4.728mg/L 的臭氧,产生了0.039mg/L 和0.045 mg/L 的溴酸盐,而用电场强度为30kV/cm的PEF处理含有0.54mg/L 溴离子质量浓度的水,未检测到溴酸盐的产生。     

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.