气相色谱-质谱法测定生姜中丙炔氟草胺残留量

本文建立了生姜中丙炔氟草胺残留量的分析方法。试样经乙腈提取,活性炭柱净化,目标农药采用气相色谱-质谱/选择离子监测法(GC-MS/SIM)进行定性、定量分析,方法检出限为0.006mg/kg,在0.02、0.04、0.05、0.1、0.2mg/kg添加水平回收率为62%～105%,相对标准偏差(RSD)5.2%～18%。     

超高效液相色谱-串联质谱法检测芹菜和土壤中灭蝇胺及其代谢物三聚氰胺残留

目的建立超高效液相色谱-串联质谱测定芹菜和土壤中灭蝇胺及其代谢物三聚氰胺残留的分析方法。方法样品以甲醇:水=4:1(V:V)混合溶液提取,经混合阳离子固相萃取柱净化,亲水作用色谱柱分离,以10mmol/L乙酸铵溶液和乙腈作为流动相进行梯度洗脱,通过电喷雾离子源正离子检测模式和多重反应监测模式测定,同位素内标法定量。结果灭蝇胺和三聚氰胺在0.01～1.0 mg/L范围内线性关系均较好,检出限为8.16×10–6～6.91×10–5 mg/kg,在0.01、0.1和1.0 mg/kg 3个添加水平下,方法回收率在81.96%～108.81%,相对标准偏差为2.83%～6.19%(n=5)。结论该方法简单、快速、准确,适合用于芹菜和土壤中灭蝇胺及其代谢物三聚氰胺的定性和定量检测。     

QuEChERS-高效液相色谱法分析稻田水及土壤中五氟磺草胺残留及其消解动态研究

目的建立稻田水及土壤中五氟磺草胺残留分析方法,研究其消解动态和残留水平。方法在安徽、黑龙江及河南三地进行农药残留田间试验。样品采用乙腈提取并净化浓缩,再经QuEChERS前处理净化,Agilent HC-C_(18)色谱柱分离,以乙腈-0.4%磷酸水为流动相进行梯度洗脱,利用高效液相色谱(high performance liquid chromatography,HPLC)检测。结果在0.02~5mg/kg的添加水平下,五氟磺草胺在稻田水中的平均回收率为88.8%~95.2%,相对标准偏差为4.0%~7.3%,最低检出浓度为0.02mg/kg;在0.02~2mg/kg的添加水平下,五氟磺草胺在土壤中的平均回收率为77.2%~90.0%,相对标准偏差为2.8%~7.5%,最低检出浓度为0.02mg/kg。实验三地的消解动态均符合一级动力学方程,五氟磺草胺在稻田水和土壤中的半衰期分别为1.9~12d和3.5~18d;8%五氟磺草胺油悬浮剂在三地水稻上以其推荐剂量的高值及其1.5倍剂量喷雾施药1次,在水稻收获期采样时测得稻田土壤中的最终残留量平均值均低于0.02mg/kg。结论由于气候、土壤类型等的不同,五氟磺草胺在安徽及黑龙江的消解半衰期存在一定差异,该研究为五氟磺草胺在水稻上的安全使用提供了科学依据。     

气相色谱-负化学离子源-质谱测定食用植物油中 3-氯丙醇酯的含量

目的建立气相色谱-负化学离子源-质谱法(gas chromatography-negative chemical ionization-mass spectrometry,GC-NCI-MS)测定植物油中3-氯丙醇酯(3-MCPDE)含量的方法。方法植物油样品经甲醇钠-甲醇水解,硅藻土固相萃取小柱净化,七氟丁酰咪唑衍生化后采用GC-NCI-MS在离子监测模式下对植物油中3-MCPDE的含量进行测定和分析,测定结果均以游离态的3-MCPD计,内标法定量。结果 3-MCPD在0.5~50μg/L质量浓度范围内线性良好(r=0.9999),定量限为0.01 mg/kg,在0.10、0.50和1.0 mg/kg 3个加标水平下的平均回收率为79.5%~81.7%,相对标准偏差为6.0%~9.2%。结论该方法准确度和精密度良好,灵敏度高,可用于食用植物油中3-MCPDE的含量测定。     

气相色谱-负化学源-串联质谱法测定动物源食品中氟虫腈及其4种代谢产物残留量

建立动物源食品(鸡蛋、鸡肉、鸡肝)中氟虫腈及其4种代谢产物(氟甲腈、氟虫腈砜、氟虫腈硫醚、酰胺氟虫腈)残留量的气相色谱-负化学源-串联质谱(gas chromatography-negative chemical ionization-tandem mass spectrometry,GC-NCI-MS/MS)测定方法。样品经乙腈(正己烷饱和)提取后,采用改进的QuEChERS净化和GC-NCI-MS/MS的多反应监测模式检测,基质匹配工作曲线法定量。实验结果表明,氟虫腈及其4种代谢产物在1~100μg/L质量浓度范围内线性良好,线性系数均大于0.999 0,氟甲腈、氟虫腈和氟虫腈硫醚定量限(RSN≥10)为0.5μg/kg,氟虫腈砜和酰胺氟虫腈定量限为1.0μg/kg。在2.0、10.0、20.0μg/kg加标水平下,回收率在80.2%~108.7%之间,相对标准偏差为3.8%~10.2%。该方法灵敏度高、准确性好,能够满足动物源食品中氟虫腈及其4种代谢产物残留量的测定。     

基质固相分散-气相色谱检测菊花中有机磷农药残留

建立菊花中14种有机磷农药残留量的气相色谱分析方法。样品用乙腈-丙酮(4:1,V/V)提取,经基质固相分散技术净化,以乙腈-甲苯(3:1,V/V)洗脱,气相色谱-火焰光度检测,外标法定量。在0.05～1.0mg/kg的添加水平,14种有机磷的平均回收率在84.54%～108.54%之间,相对标准偏差在0.66%～6.31%,该方法的检出限为0.01～0.04mg/kg。该方法的灵敏度、准确度和精密度均符合农药残留测定的技术要求。采用所建立方法测定了黄山贡菊、杭白菊和胎菊3种代表性菊花中14种有机磷农药残留量,结果表明,黄山贡菊检出乐果1.68mg/kg、毒死蜱0.17mg/kg、硫环磷0.28mg/kg,杭白菊检出毒死蜱0.09mg/kg,胎菊检出乐果0.25mg/kg、毒死蜱0.14mg/kg、伏杀磷0.08mg/kg。     

气相色谱-负化学源质谱法测定牛奶中氟虫腈及其代谢物残留

建立了气相色谱-负化学源质谱(GC-NCI-MS)测定牛奶中氟虫腈及其3种代谢物残留量的分析方法。牛奶经乙腈提取后,分散固相萃取技术QuEChERS(Quick,Easy,Cheap,Effective,Rugged,Safe)净化,HP-5MS分离,气相色谱-负化学源质谱进行测定,外标法定量。在质量浓度为2.5～100μg/L范围内,氟虫腈及其3种代谢物均有良好的线性关系,所有目标物的定量限(LQD)(S/N=10)均在0.03～0.15μg/kg范围内。样品加标质量分数为0.01,0.02 mg/kg和0.05 mg/kg时,氟虫腈及其3种代谢物的平均回收率为85.6%～102.4%,相对标准偏差(RSD)为3.6%～6.1%。该方法样品前处理简单,分析时间短,回收率和精密度等均符合氟虫腈及其3种代谢物检测技术的要求,适用于牛奶中氟虫腈及其3种代谢物残留的检测。     

HPLC-MS/MS测定玉米中异恶唑草酮及代谢物残留量

建立玉米中异恶唑草酮及代谢物残留量同时测定的高效液相色谱-串联质谱(high performance liquid chromatorgerphy-mass spectrometry/mass spectrometry,HPLC-MS/MS)分析法。试样用乙酸-乙腈(1:99, V/V)高速匀浆提取、醋酸钠和无水硫酸镁盐析后,提取液经N-丙基乙二胺(PSA)、十八烷基硅烷(ODS)和石墨化炭黑(GCB)净化,除去样品中脂肪和色素等大多数的干扰基质,用高效液相色谱-串联质谱仪检测,外标法定量。异恶唑草酮及代谢物的添加量在0.005～0.100mg/kg范围内,样品平均加标回收率在74.8%～107.2%之间,相对标准偏差为6.45%～11.15%;方法的检测限异恶唑草酮为0.01mg/kg、异恶唑草酮代谢物0.005mg/kg。本方法灵敏、准确、省时和操作简便,适用于玉米中异恶唑草酮及代谢物残留量同时检测和确证。     

改进的QuEChERS-GC-MS法快速分析茶叶中30种农药残留

本文建立了茶叶中常用的30种农药的快速分析方法。以0.1%乙酸的乙腈(V/V)作为溶剂,Agilent SampliQ提取试剂对样品进行1min提取后,用C18和Agilent SampliQ净化试剂净化,用10ml0.1%乙酸的乙腈与甲苯(体积比3:1)洗脱,气相色谱-质谱(GC-MS)检测。30种农药的检测限(LOD)为0.03μg/kg(氟草胺)～13μg/kg(苯胺灵)。采用内标法定量,添加回收试验结果表明,30种农药的平均回收率为74%～108%,相对标准偏差为0%～10.38%。该方法的灵敏度、准确度和精密度均符合农药残留测定的技术要求。     

超高效液相色谱-串联质谱法快速测定马铃薯中多种酰胺类杀菌剂方法的研究

建立了QuEChERS结合超高效液相色谱-串联质谱法测定马铃薯中氟吡菌胺、噻呋酰胺和双炔酰菌胺3种酰胺类杀菌剂残留的方法。采用电喷雾正离子模式下多反应监测(MRM)模式进行检测,基质匹配标准溶液外标法定量。结果表明,在10-500 ng/mL浓度范围内,3种杀菌剂具有良好的线性关系,R~20.991;在0.01 mg/kg、0.1 mg/kg、0.2 mg/kg三种加标水平下,平均回收率为82.7%-117.0%,RSD1%(n=6),定量限分别为0.036 1μg/kg(氟吡菌胺)、0.1676μg/kg(噻呋酰胺)、0.021 1μg/kg(双炔酰菌胺)。该方法前处理简单快速,灵敏度和准确度高,可满足马铃薯中多种酰胺类杀菌剂残留检测的要求。     

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.