盐辅助分散液液微萃取-气相色谱-串联质谱法检测葡萄酒中的氨基甲酸乙酯

目的建立了盐辅助分散液液微萃取(salt-assisted dispersive liquid-liquid microextraction,SADLLME),稳定同位素稀释,气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)检测葡萄酒中氨基甲酸乙酯(ethyl carbamate,EC)的方法。方法取30 mL葡萄酒于50 mL离心管中,加入浓度为10μg/mL的EC-d5溶液100μL和硫酸钠3 g,震荡溶解,注射针快速打入700μL二氯甲烷,震荡1 min,离心,取下层有机相,经DB-INNWAX UI色谱柱(30 m×0.25 mm,0.25μm)分离,多重反应监测方式进行质谱检测。结果方法在验证浓度范围内(5～1500 ng/mL),线性良好,r~2=0.9988,检出限为0.73μg/L,定量限为2.18μg/L,回收率为91.5%～97.8%,相对标准偏差为2.55%～5.26%。对市场上3个品牌红葡萄酒进行检测,EC含量为6.82～15.3μg/L。结论该方法样品处理简便、快速,相对绿色,定性、定量可靠,能够满足葡萄酒中EC风险监测的需要。     

水产品中三聚氰胺的快速检测方法

建立高效液相色谱法快速检测水产品中三聚氰胺的方法。样品采用50%甲醇水+1%三氯乙酸(3+1)振荡提取,高速离心后过滤进行HPLC测定。三聚氰胺在0.2μg/mL～10.0μg/mL浓度范围内线性关系良好,相关系数0.9989,加标水平在0.5mg/kg～10mg/kg范围内,回收率为85%～91%,相对标准偏差4.2%～6.4%,方法的检出限为0.5mg/kg。该方法与固相萃取前处理方法相比,过程简便、快速准确。     

分散液液微萃取-液相色谱法测定白葡萄酒中拟除虫菊酯类农药

分散液液微萃取法处理样品,结合高效液相色谱测定白葡萄酒中拟除虫菊酯类(氟氯氰菊酯、氯氰菊酯、氰戊菊酯、联苯菊酯)农药残留.二氯甲烷作萃取剂,乙醇作分散剂.色谱条件:反相C18色谱柱,甲醇∶乙腈∶水(10∶75∶15,体积比)为流动相,流速1.0mL/min,210nm紫外检测.在0.05μg/mL～50.00μg/mL范围内线性良好.相关系数均大子0.9993.平均回收率为83.20％～102.71％,相对标准偏差为1.47％～3.24％,检出限为1.00μg/L～2.00μ g/L.     

冷冻液液革取-高效液相色谱法測定可乐中的4-甲基咪唑

建立了一种冷冻液液萃取-高效液相色谱法测定可乐中4-甲基咪唑的方法。样品在碱性条件下,以乙腈作为萃取溶剂,经涡旋后,在-23℃下冷冻净化;取上清液氮气吹干,用蒸馏水定容,然后利用高效液相色谱仪在UV 210nm处检测。结果表明,该方法4-甲基咪唑的检出限和定量限分别为0.033μg/mL和0.100μg/mL;在浓度0.25μg/mL¹00μg/mL范围内,线性相关系数为0.9999;样品在1.5μg/mL、3.0μg/mL、6.0μg/mL 3个水平上,加标回收率平均值均大于85%,相对标准偏差均不超过5%(n=7),具有良好的准确度和重复性。与常规液液萃取相比,该前处理方法操作简单,有机试剂用量少,适合一次处理多个样品,具有一定的推广价值。     

液质联用技术测定茶叶中多菌灵残留

建立茶叶中多菌灵残留的高效液相色谱-串联四极杆质谱联用测定方法。该方法中样品经0.2 mol/L盐酸甲醇溶液(1∶1,υ/υ)超声提取,MCX固相萃取柱净化,以ZORBAX Eclipse XDB-C18色谱柱(3.0 mm×50 mm,1.8μm)分离,流动相为0.1%甲酸水和乙腈(梯度洗脱),电喷雾正离子MRM模式检测。该方法的检出限为1.0μg/kg,线性范围0.5μg/L～3 000μg/L,加标回收率为85.0%～96.0%,相对标准偏差为3.71%。     

饱和盐辅助-分散液液微萃取-气相色谱-串联质谱法快速筛查啤酒中氨基甲酸乙酯与9种挥发性亚硝胺

目的 建立饱和盐辅助-分散液液微萃取快速样品前处理,气相色谱-串联质谱法检测啤酒中氨基甲酸乙酯和9种挥发性亚硝胺包括N-亚硝基二甲胺、N-亚硝基二正丙胺、N-亚硝基二乙胺、N-亚硝基哌啶、N-亚硝基吡咯烷、N-亚硝基吗啉、N-亚硝基甲乙胺、N-亚硝基二丁胺和N-亚硝基二苯胺的新方法。方法 样品经甲醇提取,加入稳定同位素标记的目标物定量,在饱和碳酸钠辅助萃取下,猛力注入二氯甲烷进行SSA-DLLME,离心,取下层有机相进样,多反应监测（multiple reaction monitoring,MRM）模式进行GC-MS/MS检测,内标法定量。结果 该方法在考察的浓度范围内线性良好（r2＞0.997）,方法检出限（limits of detection,LODs）为0.10~0.34 μg/L,定量限（limits of quantitative,LOQs）为0.34~1.15 μg/L;3水平（1、5、10 μg/L）加标回收率为81.93%~119.84%,相对标准偏差(relative standard deviations,RSDs)为 0.57%~13.04% (n=8)。结论 该方法样品处理极为简便、快捷,检出限低且准确度好,可满足啤酒中EC和9种挥发性亚硝胺快速筛查检测的需要。     

分散液液微萃取结合气相色谱-火焰光度检测器法测定芝麻香型白酒中3-甲硫基丙醇

研究了超声波辅助分散液液微萃取联合气相色谱测定芝麻香型白酒中3-甲硫基丙醇。筛选优化样品前处理条件,联合气相色谱-火焰光度检测器(gas chromatography-flame photometric detector,GC-FPD)测定其含量。结果表明:分散液液微萃取参数为萃取剂三氯甲烷65μL、分散剂甲醇100μL、样品体积1 m L、样品p H值为3、酒精度12%vol、Na Cl离子强度15%、低温分离时间1 h、离心时间3.5 min,3-甲硫基丙醇提取率为93.01%。在3-甲硫基丙醇质量浓度为50~2 000μg/L时,线性相关系数为0.999 4,检测限为1.5μg/L,定量限为5μg/L。在3-甲硫基丙醇质量浓度分别为50、100、200、400μg/L四个水平下,回收率为92.11%~101.90%。检测5个白酒样品中3-甲硫基丙醇含量,质量浓度分别为110.41~1 238.67μg/L,其中孔府家酒含量最高。     

气相色谱-质谱法测定质控样品鱼肉粉中N-亚硝基二甲胺含量

目的：建立测定食品中N-亚硝基二甲胺(N-Nitrosodimethylamine, NDMA)含量的快速气相色谱串联质谱法。方法：利用气质联用法对质控样品鱼肉粉中NDMA进行检测，将GB 5009.26—2016中方法1的全玻璃蒸馏装置改成定氮仪单步蒸馏。结果：结果表明，在NDMA质量浓度范围为0.01～0.5μg/mL时，线性关系良好，相关系数R²=0.998，精密度实验计算相对标准偏差为4.6%，平均回收率为100.4%。该方法检出限为0.2μg/kg。结论：采用的蒸馏装置符合检测要求，具有密闭性好、效率高、蒸馏速度快等优点。可用于亚硝胺类化合物标准样品的质控考核，测定结果均在保证值范围内，准确度高。适用于食品中亚硝胺类化合物的检测。     

液液萃取-高效液相色谱法测定红茶中赭曲霉毒素A

目的：建立一种液液萃取净化的高效液相色谱法测红茶中的赭曲霉毒素A的方法。方法：试样经60%乙腈超声提取，液液萃取净化，以甲醇～0.5%乙酸梯度洗脱，C18短柱分离后经高效液相色谱仪-荧光检测器检测。结果：赭曲霉毒素A在10.00μg/L～50.00μg/L浓度范围，相关系数为1.00000，加标回收率为83%～98%,RSD为1.11%～2.47%，检出限为0.0052mg/kg。结论：仪器20min完成一个样品测定，方法检测速度快，同时具有净化效果好，精密度和准确度高的特点。     

利用气液微萃取技术联用气相色谱-质谱法检测谷类中27种残留农药

目的建立气液微萃取技术(gas-liquid microextraction,GLME)联用气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)快速检测谷类中的27种农药残留的方法。方法精确称量0.5 g谷类样品,用0.5 mL二氯甲烷溶剂超声萃取15 min,离心4 min后取上清液100μL,利用气液微萃取(GLME)对27种农残萃取、净化和浓缩,结合内标法确保结果的准确性。结果 27种农药在0.001～1.0mg/kg浓度范围内线性良好,相关系数在0.9990～0.9999,检出限为0.002～0.026 mg/kg,定量限为0.0007～0.086 mg/kg,平均回收率为71.2%～124.4%(n=3),相对标准偏差在0.2%～18.8%之间。结论本方法操作简便方便、准确度高、重现性好,适用于食品安全现场检测和快速检测,对于保障我国食品安全构建完整的食品安全检测体系具有重大意义。     

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.