LC-MS/MS测定茶叶中吡虫啉和啶虫脒残留量

茶叶采用乙腈提取,C18,SPE小柱净化,液相色谱-串联质谱法测定茶叶中吡虫啉和啶虫眯。色谱柱为ZORBAX,XDB C18,5μm,4．6mm×150mm,流动相为乙腈-0．1％甲酸梯度洗脱。结果表明：该方法定性、定量准确,灵敏度高,最低检出限为0.01mg／kg,加标回收率吡虫啉80％～90％,啶虫脒76％-88％,RSD（n=5）为吡虫啉为6．84％～7．25％,啶虫眯为7．90％～9．92％,具有操作简单、速度快、准确度高、色谱分离效果好、对环境污染少的特点。     

固相萃取-高效液相色谱-串联质谱法测定茶叶中啶虫脒、吡虫啉和氟虫腈残留量

目的建立茶叶中吡虫啉、啶虫脒和氟虫腈三种农药残留的固相萃取-高效液相色谱-串联质谱测定方法。方法样品用水浸泡,乙腈提取,经石墨化碳-氨基复合固相萃取小柱净化,采用Agilent Eclipse AAA色谱柱分离,以0.1%乙酸水溶液和乙腈为流动相梯度洗脱,正、负离子切换扫描,多反应监测(MRM)模式检测,外标法定量。结果在3个添加水平下,吡虫啉、啶虫脒和氟虫腈的平均回收率分别为78.8%~91.5%,81.3%~92.8%,和72.8%~90.0%;相对标准偏差分别为2.6%~10.6%,3.7%~6.6%和3.6%~7.4%。啶虫脒、吡虫啉和氟虫腈的检出限均为0.5μg/kg,定量限为2μg/kg。结论建立的方法简便、快速,灵敏度高,可满足出口茶叶中吡虫啉、啶虫脒和氟虫腈残留同时检测的要求。     

高效液相色谱-串联飞行时间质谱法测定茶叶中6种农药的残留量

建立了茶叶中噻嗪酮、毒死蜱、啶虫脒、吡虫啉、乐果、多菌灵等6种农药残留量的高效液相色谱-串联飞行时间质谱检测方法。茶叶样品经酸化乙腈提取,基质分散固相萃取净化。经高效液相色谱分离后进入飞行时间质谱检测。6种农药浓度在1～50μg/kg下线性关系良好,相关系数R2在0.995～0.999之间,检测限在0.01～1μg/kg之间,回收率在80%～102%之间,相对标准偏差(RSD)在4%～6%之间。该方法快速、准确、灵敏度高,能够满足茶叶中多种农药残留的定性、定量检测需求。     

超高效液相色谱-质谱联用法测定山野菜中5种农药的残留

建立超高效液相色谱-质谱联用法[ACQUITY UPLC/Xevo TQ-S]测定人工栽培山野菜中啶虫脒、吡虫啉、多菌灵、嘧霉胺、苯醚甲环唑5种农药残留。以乙腈为提取溶剂,采用多重反应离子监测(MRM)模式,ACQUITY UPLC BEH C18为分析色谱柱、0.1%甲酸乙酸铵-乙腈为流动相,对样品进行检测分析。结果表明:5种农药在0.0005~2.0000 mg/L范围内与峰面积呈良好线性关系,相关系数在0.9947~0.9999之间。在农药混合标准溶液0.005~0.200 mg/kg的水平下,添加回收率均在73.43%~115.84%之间,相对标准偏差为2.04%~18.19%。检出限在0.020~0.510μg/kg范围内;定量限在0.066~1.699μg/kg范围内。本方法操作简单、快捷、准确度和精密度高,可应用于山野菜中5种农药残留测定。     

凝胶渗透色谱-超高效液相色谱-串联质谱测定茶叶中吡虫啉和啶虫脒

建立用凝胶渗透色谱-超高效液相色谱-串联质谱仪测定茶叶中吡虫啉和啶虫脒残留的方法。样品经乙酸乙酯-环己烷（1∶1,V/V）溶液涡旋混匀后超声提取,经凝胶渗透色谱净化后,采用超高效液相色谱-串联质谱仪测定。结果显示,2 种农药在0.5～100 μg/L范围内线性良好,相关系数R2均大于0.99。吡虫啉和啶虫脒的检出限分别为2.0 μg/kg和1.0 μg/kg,定量限分别为5.0 μg/kg和3.0 μg/kg。吡虫啉和啶虫脒在3 个水平的加标平均回收率为76.94%～91.68%,相对标准偏差为2.67%～7.90%。     

液相色谱-串联质谱法测定茶叶中的11种农药残留

目的建立液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)测定茶叶中11种农药残留的分析方法。方法样品经乙腈提取,经石墨化炭黑/N-丙基乙二胺复合型固相萃取柱(graphite carbon black/primary secondary amine,GCB/PSA)净化,用液相色谱-串联质谱法测定。结果 11种农药浓度在0.005~0.20μg/m L范围内线性良好,线性相关系数均大于0.997,在0.01、0.05和0.10 mg/kg的添加水平下,回收率为66.0%~100.0%,相对标准偏差为2.2%~10.0%。结论本方法简便、快速、准确,适用于茶叶样品中11种农药残留量的检测。     

高效液相色谱-串联质谱法测定中草药中多种 新烟碱类农药的残留量

目的建立液相色谱-串联质谱分析法同时测定中草药夏枯草、野菊花、金银花、苏银花中噻虫嗪、氯噻啉、吡虫啉、啶虫脒、噻虫胺、噻虫啉6种新烟碱类农药残留量。方法样品中的6种新烟碱类杀虫剂经乙腈提取,QuEChERS方法净化后,液相色谱-串联质谱法分离和测定,外标法定量。结果方法检出限为0.1～4.8μg/kg,在方法的检测限与200 ng/mL测定范围内有良好的线性关系(r0.9990),在所添加5个水平浓度下,方法的回收率在70.4%～108.3%,相对标准偏差在1.0%～8.8%。结论该方法准确、简单、快速,适用于中草药中多种新烟碱类农药的同时检测。     

LC-MS/MS法测定枸杞中啶虫脒、吡虫啉农药残留的方法学研究

目的:枸杞是一种药食两用的中药材,人们经常食用枸杞来提高身体免疫力。本论文以枸杞为研究对象,建立了液相色谱-串联质谱法,以同时测定啶虫脒、吡虫啉农药残留量。     

UPLC-MS/MS检测果蔬饮料中痕量吡虫啉

建立一种快速、有效的超高效液相色谱-串联质谱法测定果蔬饮料中痕量吡虫啉农药残留的方法。样品经0.1%醋酸-乙腈提取后,采用氨基固相萃取小柱进行净化和富集。采用Waters Atalantis T3色谱柱(2.1 mm×150 mm,3μm)分离,以0.1%甲酸-乙腈为流动相的梯度洗脱模式下,吡虫啉标准在0.5 ng/mL~50.0 ng/mL浓度范围内线性良好,相关系数r~2为0.999,检出限为0.15μg/kg,定量限为0.50μg/kg,加标回收率达到93.2%~96.9%。     

基于动态多反应监测模式下的高效液相色谱-串联质谱法同时测定枸杞中44种农药残留

目的:建立一种基于动态多反应监测模式同时检测枸杞中44种农药残留的高效液相色谱-串联质谱的分析方法。方法:样品经10 mL超纯水复水,用0.1%甲酸-乙腈提取,经PSA、C₁₈、MgSO₄填料净化,T3色谱柱分离,0.1%甲酸水和乙腈流动相体系梯度洗脱,在正离子模式下采用动态多反应监测模式(d-MRM)检测,基质匹配外标法定量。结果:44种农药在0.002~0.200 mg/L范围内线性关系良好(R2>0.9943),方法检出限范围为0.01~3.30 μg/kg,3个添加水平的回收率为60.2%~115.3%,相对标准偏差为0.63%~8.27%。测定了市售枸杞样品20批,共检出农药残留14种,其中多菌灵、啶虫脒、吡虫啉的检出率高达95%。结论:该方法操作快速、简便、准确、可靠,适用于枸杞中44种农药残留的同时检测。     

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.