多壁碳纳米管QuEChERS结合超高效液相色谱-串联质谱法测定鸡蛋中兽药多残留

目的基于改良的多壁碳纳米管QuEChERS方法,建立超高效液相色谱-串联质谱法快速筛查和测定鸡蛋中38种兽药残留量。方法样品以70%乙腈提取,结合多壁碳纳米管、十八烷基键合硅胶、乙二胺-N-丙基硅烷混合吸附剂净化提取液,以1%甲酸水和1%甲酸甲醇为流动相,经CAPCELLPAKC18MGⅢ(2.0mm×100mm,1.1μm)分离,采用电喷雾正负离子多反应监测模式检测,基质匹配外标法进行定量。结果 38种化合物在0.1～100.0μg/L范围内线性关系良好(r 0.99);在3个添加水平下,平均回收率为80.1%～113.8%,相对标准偏差为1.1%～9.8%,定量限为0.014～1.100μg/kg。结论该方法简便,基质干扰小,可用于鸡蛋中磺胺类、氯霉素类、氟虫腈类以及硝基咪唑类药物快速筛查和定量分析。     

多壁碳纳米管净化-超高效液相色谱-串联质谱法测定鸡蛋中44种药物残留

建立超高效液相色谱-串联质谱(HPLC-MS/MS)法同时测定鸡蛋中44种药物的残留量。样品加入乙腈沉淀蛋白后,再经多壁碳纳米管、十八烷基键合硅胶、乙二胺-N-丙基硅烷组合技术净化后,以0.1%甲酸溶液-0.1%甲酸甲醇为流动相进行梯度洗脱分离,以电喷雾离子源在正、负离子多反应监测模式下进行测定,用基质匹配标准曲线外标法定量。结果表明,44种药物在0.1~200 ng/mL范围内线性良好,R2为0.9909~0.9999,方法检出限0.007~0.3571 μg/kg,定量限为0.005~1.190 μg/kg,样品回收率在77.9%~114.5%,相对标准偏差小于10%(n=6)。该方法操作简便,灵敏度高,适用于鸡蛋中药物残留的高通量筛查。     

改良QuEChERS结合超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法测定果蔬中15种植物生长调节剂残留

基于改良的QuEChERS方法,建立超高效液相色谱-四级杆/静电场轨道阱高分辨质谱法(UPLC-Q-Orbitrap HRMS)快速筛查和测定果蔬中15种植物生长调节剂残留的方法。样品以1%乙酸乙腈提取,多壁碳纳米管(MWCNTs)净化,采用Hypersil GOLD aq C₁₈色谱柱(2.1 mm×100 mm,1.9 μm)进行分离,乙腈和水(含0.1%甲酸-5 mmol/L甲酸铵)为流动相梯度洗脱,质谱采用全扫描/数据依赖的二级扫描模式,基质匹配校准曲线定量。结果显示:15种化合物在2.0~500.0 μg/L范围内,线性关系良好(r>0.990);在3个加标水平下,平均回收率为70.3%~107.2%,相对标准偏差(RSD)为1.4%~9.9%,定量限为10.0~20.0 μg/kg。该方法简单,灵敏度高,准确可靠,可对果蔬中植物生长调节剂进行快速筛查和定量分析。     

PRiME HLB固相萃取-高效液相色谱-串联质谱法同时快速测定鸡蛋中48种兽药残留

建立固相萃取-高效液相色谱-串联质谱同时快速测定鸡蛋中48种兽药残留的分析方法。样品采用90%乙腈水溶液提取,用PRiME HLB小柱净化浓缩后用电喷雾离子源,正负离子扫描,多反应监测模式的高效液相色谱-串联质谱法进行检测,以基质匹配曲线外标法定量。正离子采用CAPCELL PAK C18 MGⅢ-H色谱柱,流动相为0.05%甲酸乙腈和0.1%甲酸水;负离子采用ACQUITY UPLC BEH C18色谱柱,流动相为5 mmol/L乙酸铵和乙腈。结果表明,鸡蛋样品中的48种兽药残留在0.5~50 μg/kg浓度范围内线性关系良好,相关系数(r)为0.9952~1.0000。方法检出限为0.01~0.55 μg/kg,定量限为0.03~1.83 μg/kg,样品回收率在63.3%~111.4%之间,相对标准偏差小于10%(n=3)。本方法操作快速简单,重复性好,灵敏度较高,适用于鸡蛋中48种兽药残留的快速筛查检测。     

通过式净化-液相色谱-串联质谱快速筛查水产品中15类107种兽药多残留的方法研究

目的 建立水产品基质中15类包含107种药物多残留的快速筛查方法。方法 通过多溶剂分步提取-通过式净化, 结合液相色谱-串联质谱仪, 在MRM模式下正、负离子同时扫描监测水产品, 实现水产品中15类107种药物多残留的快速筛查, 并用于实际水产样品中药物残留含量的测定。结果 所有药物在35 min内分离良好, 方法线性范围为0.1~200 ng/mL, 相关系数均大于0.995; 检出限为0.1~5.0 μg/kg (S/N>3), 定量限为0.3~10 μg/kg (S/N>10); 回收率为40.0%~120%, 相对标准偏差均小于15%。结论 方法的准确性和灵敏度较高, 重现性好, 适合水产基质中药物多残留的高通量、快速筛查, 能够满足国家限量法规的要求。     

超高效液相色谱-四极杆飞行时间质谱法快速测定畜禽产品中抗组胺类药物残留

建立超高效液相色谱-四极杆飞行时间质谱（UPLC-Q-TOF/MS）快速测定畜禽产品中19种抗组胺类药物及代谢物残留的方法。样品用乙腈-乙酸乙酯溶液提取,提取液经增强型脂质去除剂（EMR）结合经氧化修饰的多壁碳纳米管（MWCNTs）净化,以0.1%甲酸水-0.1%甲酸乙腈作为流动相进行梯度洗脱,在EclipsePlus-C₁₈（50 mm×2.1 mm,1.8 μm）色谱柱上分离,柱温40℃,流速0.3 mL/min,进样量5 μL,Q-TOF/MS电喷雾正离子模式分析检测。在全扫描模式下采集一级质谱数据,以待测物的准分子离子峰的峰面积定量,以保留时间、精确质量数、同位素丰度比等特征信息定性。在Target MS/MS模式下靶向采集二级质谱数据,通过特征碎片离子的精确质量数等信息进一步确证。结果表明,所有药物在浓度范围内线性良好,决定系数均大于0.996,不同阴性样品基质中（牛肉、鸡肉、猪肝）在3个浓度水平加标试验回收率在78.2%~105.3%之间,相对标准偏差（RSD）为3.2%~8.2%,方法检出限（LOD,S/N≥3）为0.5~2.0 μg/kg,定量限为1.5~6.0 μg/kg。本方法简便快速,灵敏度高,选择性好,结果准确,适用于畜禽产品中19种抗组胺类药物及代谢物的快速筛查和定量测定。     

QuEChERS EMR-Lipid技术结合LC/MS/MS快速筛查与确证猪肉中55种兽药残留

运用QuEChERS Enhanced Matrix Removal(EMR)-Lipid技术作为前处理方法,通过高效液相-三重四极杆质谱联用技术建立猪肉中55种兽药残留的快速检测方法。样品采用5%甲酸乙腈进行提取,经QuEChERS EMR-Lipid净化,氮吹浓缩后的溶液通过Agilent Eclipse Plus C₁₈(150 mm×3.0 mm,1.8 μm)进行分离,在三重四极杆正离子动态多反应监测模式下进行检测,通过保留时间及离子对丰度比进行快速筛查和确证,并采用基质标准曲线定量。结果表明,55种化合物在30 min内完成分离,在1.25~250 ng/mL范围内线性关系良好,相关系数r≥0.998,定量限均为1 μg/kg,在1~100 μg/kg加标回收中,回收率在60.5%~139.5%,RSD在1.0%~20.1%(n=6)。本方法简单、快捷、高效,适用于猪肉中多兽药残留的快速筛查与确证。     

多壁碳纳米管结合气相色谱-电子捕获检测法同时测定茶叶中18种有机氯类农药残留

目的 将多壁碳纳米管(MWCNTs)净化的QuEChERS前处理技术与气相色谱-电子捕获检测器(GC-ECD)结合,建立了茶叶中18种有机氯农药残留的分析方法。方法 样品经丙酮提取,基于MWCNTs改良QuEChERS方法净化,Rtx-5色谱柱分离,电子捕获检测器检测,基质外标法定量。优化了提取条件、净化剂的种类与用量。结果 优化实验条件下,18种有机氯农药在0.01~0.10 μg/mL范围内具有良好的线性关系,基质校准曲线相关系数r均不小于0.99;3个添加水平下的平均加标回收率为85.2~119.9%,相对标准偏差(RSDs)为0.61~6.77% (n=6)。方法检出限为10~18 μg/kg,定量限为15~23 μg/kg。结论 该方法操作简单、准确度和精密度好,为茶叶中有机氯类多农残快速分析提供了新方法。     

超高效液相色谱-串联质谱法测定果蔬中28种植物生长调节剂残留量

目的 建立一种超高效液相色谱-串联质谱法快速测定果蔬中28种植物生长调节剂(plant growth regulators, PGRs)残留量的方法。方法 样品经1%甲酸乙腈提取, QuEChERS方法净化后, 根据样品状态, 最后再经过MPFC -QuEChERS超滤净化柱进行滤过式净化。采用5 mmol/L乙酸铵0.1%甲酸水溶液-乙腈 梯度洗脱, Hypersil GOLD柱进行分离, 多反应监测模式正负离子切换扫描, 用上海青、豆芽、苹果三种基质 分别匹配标准曲线, 外标法定量。结果 三种代表基质匹配的曲线在20~300 ng/mL范围内线性关系良好, r≥0.990, 在4、20、60 μg/kg 三个不同加标浓度下, 平均回收率为60.49%~120.96%，RSD为0.3%~14.6%, 定量限为0.09~4.06 μg/kg 。结论 该方法快速、准确、干扰小, 可满足实验室对于常见类别果蔬的植物生长调节剂进行快速筛查。     

多壁碳纳米管QuEChERS-液相色谱-串联质谱法快速检测茶叶中氯虫苯甲酰胺残留量

目的 建立多壁碳纳米管QuEChERS-高效液相色谱-串联质谱法测定茶叶中氯虫苯甲酰胺残留量的分析方法。方法 样品经乙腈提取,多壁碳纳米管QuEChERS方法净化,经Agilent Eclipse Pluse C₁₈色谱柱( 2.1 mm× 50 mm,1.8 μm),以0.1%甲酸水(A)-乙腈(B)为流动相进行梯度分离,并在串联质谱正离子多反应监测模式(MRM)下进行测定,空白基质配标外标法定量。结果 5种茶叶中氯虫苯甲酰胺在0.100～50.0 ng/mL的范围内线性良好(r＞0.995),检出限为0.50 μg/kg, 定量限为1.2μg/kg, 在0.500、5.00、500 μg/kg添加水平下, 平均加标回收率在84.4%~103.9%之间, 相对标准偏差为0.8%~8.3% (n=6)。结论：该方法具有较高的灵敏度,操作简便,测定结果准确可靠,可用于茶叶中氯虫苯甲酰胺农药残留量的检测。     

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.