离子色谱法(抑制电导)测定面粉中溴酸盐的含量

研究建立了离子色谱抑制电导测定面粉中溴酸盐的新方法。BrO3^-标准曲线的线性范围为0．05～5mg／L（r=0．9999）,方法的加标回收率为81．7％～94．8％,相对标准偏差为2．3％,样品中BrO3^-的检出限为40μg／kg（以20g称样量计算）。实验表明,该方法快速、灵敏、准确,适合面粉中溴酸盐的测定。     

离子色谱-串联质谱法测定生活饮用水中的高氯酸盐、氯酸盐和溴酸盐

目的建立离子色谱-串联质谱法同时测定生活饮用水中高氯酸盐、氯酸盐和溴酸盐含量的分析方法。方法选用高容量、亲水性IonPacAS-20阴离子交换柱为分析柱对高氯酸盐、氯酸盐和溴酸盐进行分离,以淋洗液自动发生器在线产生KOH为淋洗液进行洗脱。采用外接水模式,串联质谱进行检测。采用电喷雾离子源负离子模式和多反应监测测定,外标法定量。结果高氯酸盐、氯酸盐和溴酸盐的线性范围分别为0.04～20.00μg/L, 0.02～10.00μg/L, 0.04～20.00μg/L,相关系数r~20.999,检出限分别为0.02、0.01和0.02μg/L,定量限分别为0.04、0.02和0.04μg/L,加标回收率在90.0%～98.8%,相对标准偏差(relative standard deviation,RSD)小于8.0%。结论该方法简便、可靠、稳定、灵敏度高,可用于生活饮用水中高氯酸盐、氯酸盐和溴酸盐含量的快速测定与确认。     

高效液相色谱和高效液相色谱-离子阱质谱测定花生、玉米和大米中黄曲霉毒素方法比较

比较花生、玉米和大米中黄曲霉毒素(AFT)测定的两种分析方法。样品经70%甲醇溶液(含NaCl 4g/100mL)提取,自制免疫亲和柱净化。洗脱液一分为二,一份经正己烷、三氟乙酸衍生后用配有荧光检测器的液相色谱检测;另一份无需衍生用液相色谱-串联离子阱质谱检测。液相色谱测定的AFB1、AFB2、AFG1和AFG2的检出限(RSN=3)分别为0.5～1.5μg/kg,相关系数在0.9979～0.9999,加标回收率50.29%～126.54%;液相色谱-串联质谱测定的AFB1、AFB2、AFG1和AFG2的检出限分别为0.1～0.2μg/kg;相关系数在0.9993～0.9998,加标回收率50.38%～121.27%。结果表明液相色谱-离子阱质谱法无论在选择性还是在灵敏度上都优于高效液相色谱。     

离子色谱法同时测定饮用水中的溴酸盐和高氯酸盐

建立离子色谱同时测定饮用水中溴酸盐和高氯酸盐的方法。通过加热浓缩对水样中的Br O3-和Cl O4-进行富集,选用亲水性AS19分析柱作为分离柱、氢氧化钾溶液为淋洗液,优化离子色谱测试条件后,采用电导检测器测定水中溴酸盐和高氯酸盐的含量。结果表明,当进样体积为100μL时, Br O3-和Cl O4-浓度分别在5～125μg/L、0.02～1.25 mg/L范围内与其对应的峰面积呈线性关系,线性回归方程分别为y=0.000 21C-0.000 23、y=0.302 98C-0.005 27,相关系数分别为0.999 8和0.999 9,方法检出限分别为0.50μg/L和5.2μg/L。对每份样品进行3个水平的加标回收试验,加标回收率均在90.33%～103.79%之间,测定结果的相对标准偏差在0.34%～4.46%之间,并与液相色谱-质谱/质谱法的测定结果进行比较,结果无显著性差异。方法具有准确度高、选择性好和操作简单等优点,可应用于多种饮用水中溴酸盐和高氯酸盐含量的同时测定。     

高效液相色谱-串联质谱法测定猪肉中3种β-受体激动剂残留量

目的建立猪肉中3种β-受体激动剂(沙丁胺醇、莱克多巴胺、克伦特罗)残留量的高效液相色谱-串联质谱联用检测方法。方法样品经SPE柱净化处理后,以乙酸胺和乙腈为流动相梯度洗脱,电喷雾离子化为离子源,多反应检测方式,使用高效液相色谱-串联质谱仪测定。结果 3种β-受体激动剂在0.5～10.0μg/L范围内呈良好线性关系,相关系数均大于0.999,检出限为0.13～0.15μg/kg,加标回收率在79.25%～112.82%之间,相对标准偏差在7.14%～17.80%之间。结论建立的方法专属性好,灵敏度高,检出限低,操作可行,可实现动物源性食品中多种β-受体激动剂残留量的同时测定。     

气相色谱-串联质谱法测定婴幼儿配方乳粉中的3-氯丙醇酯和缩水甘油酯及其风险评估

建立检测婴幼儿配方乳粉中3-氯丙醇酯和缩水甘油酯的气相色谱-串联质谱法,测定不同市售婴幼儿配方乳粉中3-氯丙醇酯和缩水甘油酯的含量,掌握婴幼儿配方乳粉中酯类污染情况并进行安全风险评估。采用正己烷提取婴幼儿配方乳粉中的3-氯丙醇酯和缩水甘油酯,经过水解、苯基硼酸衍生、气相色谱-串联质谱法测定,内标法定量。结果表明,3-氯丙醇酯和缩水甘油酯总量在0.040 0～4.00μg/m L、3-氯丙醇酯含量在0.020 0～2.00μg/m L的范围内线性良好,相关系数R²>0.999,检出限均为10.0μg/kg,定量限均为25.0μg/kg。在25.0、100、300μg/kg添加水平下,平均回收率在95.0%～98.1%之间。该方法准确率高、回收率好,可用于婴幼儿配方乳粉中的3-氯丙醇酯和缩水甘油酯的检测。150份市售婴幼儿配方乳粉样品中,3-氯丙醇酯检出率为12.7%,含量为ND～52.4μg/kg,平均检出值为29.8μg/kg。缩水甘油酯检出率为6.67%,含量为ND～40.1μg/kg,平均检出值为31.9μg/kg。3-氯丙醇酯的平均暴露水平为0.33～...     

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。     

液相色谱-串联质谱法测定饮用水中的卤氧化物

目的建立一种液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,LC-MS/MS)同时检测饮用水中3种卤氧化物(高氯酸盐、氯酸盐及溴酸盐)的分析方法。方法水样直接经0.22μm水系滤膜过滤,采用100 mmol/L乙酸铵(A)和乙腈(B)作为流动相进行等度洗脱,经IC-Pak~(TM) Anion HR色谱柱分离,质谱(ESI-)采用多离子检测模式(MRM)对3种卤氧化物的定量离子和定性离子进行监测。结果本方法在6min内即完成3种目标化合物的分离分析。高氯酸盐及溴酸盐在0.5~50μg/L浓度范围内线性良好、氯酸盐在0.5~100μg/L浓度范围内线性良好(r≥0.999)。添加浓度为0.5、10.0、50.0μg/L,实验结果表明高氯酸盐、氯酸盐及溴酸盐的回收率可达84.8%~101.4%,相对标准偏差均小于10.0%(n=6)。高氯酸盐、氯酸盐及溴酸的检出限分别为0.1、0.2、0.2μg/L。结论该方法快速、准确、灵敏,适合测定饮用水中高氯酸盐、氯酸盐及溴酸盐的同时测定。     

液相色谱-串联质谱法测定鸡肉和鸡蛋中3种硝基咪唑类药物

目的优化液相色谱-串联质谱法测定鸡肉及鸡蛋样品中地美硝唑(dimetridazole,DMZ)、甲硝唑(metronidazole, MNZ)、替硝唑(tinidazole, TDZ)3种硝基咪唑类药物。方法样品经过乙酸乙酯提取,氮吹浓缩,盐酸水溶液复溶,正己烷除脂,固相萃取柱净化,以乙腈-0.1%乙酸水溶液为流动相, SB-Aq色谱柱分离,液相色谱串联质谱法在多重反应监测(multiple reaction monitoring, MRM)正离子模式下检测,外标法定量。结果鸡肉、鸡蛋标准曲线在1～500μg/kg的浓度范围内线性关系良好,相关系数r0.999,方法的回收率在67.56%～97.91%之间,相对标准偏差为0.90%～16.27%,定量限(S/N=10)为5μg/kg,检出限(S/N=3)为1μg/kg。结论本方法样品前处理简单,精密度、重复性和回收率较好,适用于批量测定鸡肉及鸡蛋样品中3种硝基咪唑类药物。     

超高效液相色谱-串联质谱法测定减肥类保健食品中3种违法添加的缓泻药成分的含量

目的建立超高效液相色谱-串联质谱法测定减肥类保健食品中脱乙酰比沙可啶、双醋酚丁和比沙可啶3种违法添加的缓泻药含量的方法。方法样品用甲醇超声提取后,十八烷基硅烷键合硅胶色谱柱分离,乙腈-0.1%甲酸水作为流动相洗脱,以电喷雾离子源正离子模式电离,结合多反应监测模式采集多个离子对进行测定。结果 3种缓泻药成分在1.0～100μg/L范围内线性关系良好,相关系数均大于0.9991,平均回收率为82.8%～94.6%,相对标准偏差为4.52%～6.33%,方法检出限均为25μg/kg,定量限均为80μg/kg。结论该方法回收率高,灵敏度高,重现性好,操作简便,适用于实验室的批量测定。     

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.