超高效液相色谱串联质谱法测定豆芽中15种喹诺酮类药物

采用超高效液相色谱串联质谱同时测定绿豆芽和黄豆芽中15种喹诺酮类药物的含量。样品经0.1 mol/L的EDTA-Mcllvaine缓冲溶液提取后,经Waters Oasis HLB固相萃取小柱净化,氮吹复溶后,采用Agilent Eclipse Plus C_(18)柱(150 mm×3.0 mm,1.8 μm)分离,以0.2%甲酸乙腈和0.2%甲酸水为流动相梯度洗脱,采用电喷雾离子源正离子动态多反应监测模式测定,外标法定量。2种豆芽基质中15种喹诺酮类药物的线性范围为5～120 μg/kg,相关系数大于0.9996,方法检出限均为5 μg/kg。15种喹诺酮在3个加标水平下平均回收率为64%～120%,相对标准偏差(n=6)0.13%～3.96%。采用该方法对400批豆芽进行检测分析,喹诺酮类药物残留检出率达到21.3%。结果表明该方法简单、灵敏、准确,实用性强,可用于豆芽中15种喹诺酮类药物残留的测定。     

高效液相-示差折光法比较新疆地产8种蜂蜜中4种糖的含量

目的研究比较新疆地区8种蜂蜜中果糖、葡萄糖、蔗糖、麦芽糖的含量,以评价其质量。方法依据国标检测方法(GB/T18932.22-2003)并依据文献加以改进。采用Waters carbohydrate high performance(4.6mm×250 mm,4μm)色谱柱,乙腈:水(75:25,V:V)为流动相,流速:1.0 m L/min,柱温:35℃,检测器为示差折光检测器,进样量为10μL。结果混标及蜂蜜样品中的果糖、葡萄糖、蔗糖和麦芽糖在10 min内均达到基线分离,加样回收率为98.6%~102.6%,相对标准偏差(RSD)为1.5%~2.6%,有7种蜂蜜中果糖、葡萄糖含量均大于30%,蔗糖含量低于2%。结论该方法与国标检测方法相比具有灵敏度高,分析时间短,结果准确可靠,适用于蜂蜜中单糖的快速分析和质量控制。     

液相色谱-串联质谱法检测蜂蜜中15种喹诺酮类和17种磺胺类药物残留

目的建立同时测定蜂蜜中15种喹诺酮和17种磺胺类药物残留的液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)检测方法。方法样品经过磷酸盐缓冲溶液(pH=8)提取,过HLB(hydrophile-lipophile balance)固相萃取柱净化。以CORTECS C18色谱柱(2.1 mm×100 mm,1.6μm)分离,以5 mmol乙酸铵、0.1%甲酸水(A)和0.1%甲酸-乙腈(B)作为流动相进行梯度洗脱。质谱分析以电喷雾为离子源(electrospray ionization,ESI+),采用多反应监测(multiple reaction monitoring,MRM)。结果本方法在15 min内完成32种目标化合物的分离。15种喹诺酮和17种磺胺类药物在1.0、5.0和10.0μg/kg添加水平的回收率为54.9%~122.5%,相对标准偏差(relative standard deviation,RSD)小于18.7%(n=6),方法检出限为0.4μg/kg,定量限为1.0μg/kg。结论该方法快速、准确、灵敏,适合测定蜂蜜中喹诺酮和磺胺类药物残留。     

UPLC-MS/MS法测定蜂蜜中4种喹诺酮类药物残留

本研究旨在建立UPLC-MS/MS法测定蜂蜜中4种喹诺酮类药物残留。方法:蜂蜜样品用80%甲醇水溶解,经Prime HLP固相萃取柱净化,超高效液相电喷雾串联四级杆质谱检测,外标法定量。结果:本方法在10、25、50 ng/mL添加水平的回收率为为72.48%～103.22%,RSD均不大于10.00%。结论:在最佳色谱条件下,本研究建立的UPLCMS/MS法具有较好的线性、回收率和精密度,可用于测定蜂蜜中4种喹诺酮类药物残留。     

高效液相-示差折光法比较新疆地产8种蜂蜜中单糖的含量

目的 本文依据国标检测方法(GB/T18932.22-2003)并依据文献对其改进研究比较新疆地区8种蜂蜜中果糖、葡萄糖、蔗糖的含量,评价其真伪和质量。方法 采用 Waters carbohydrate high performance(4.6 mm×250 mm,4 μm),乙腈：水(75:25,V:V)为流动相,流速：1.0 mL/min,柱温：35℃,检测器为示差折光检测器,进样量为10 μL。结果 混标及蜂蜜样品中的果糖、葡萄糖、蔗糖和麦芽糖在10 min内均达到基线分离,加样回收率分别为98.6%～102.6%,相对标准偏差(RSD)分别为1.5%～2.6%,并且8种蜂蜜中果糖、葡萄糖含量均大于30%,蔗糖含量低于2%。结论 8中蜂蜜中山花蜂蜜果糖含量最高,枸杞蜂蜜葡萄糖含量最高,并且国标检测方法灵敏度高,分析时间短,结果准确可靠,适用于蜂蜜中糖的快速分析和质量控制。     

同位素稀释法-超高效液相色谱-串联质谱法测定豆芽中6种喹诺酮类药物残留

目的建立通过式固相萃取(solid phase extraction,SPE)柱净化、氘代同位素内标、超高效液相色谱-串联质谱法同时测定豆芽中6种喹诺酮类药物残留的方法。方法用0.1%甲酸-乙腈作为提取溶剂,经通过式固相萃取柱净化提取液,超高效液相色谱-串联质谱测定豆芽中6种喹诺酮药物残留。结果 6种喹诺酮在5.0～200μg/L范围内线性关系良好,r~2≥0.999;方法检出限(S/N=3)为0.7μg/kg,定量限(S/N=10)为2.0μg/kg;加标水平为2.0～80μg/kg时,平均回收率在85.5%～119.4%,相对标准偏差(relative standard deviation,RSD)(n=6)为0.13%～9 93%。结论本方法前处理简单,定量结果准确,回收率高,可以应用于大批次豆芽中喹诺酮药物残留的监测。     

超高效液相色谱-串联质谱法同时测定蜂蜜中8种生物胺

建立了同时测定蜂蜜中色胺(TR)、2-苯乙胺(PHE)、腐胺(PUT)、尸胺(CAD)、组胺(HIS)、酪胺(TYR)、亚精胺(SPD)和精胺(SP)8种生物胺的超高效液相色谱串联质谱柱前衍生的分析方法。样品经5%三氯乙酸溶液提取后用丹磺酰氯柱前衍生,采用Agilent Poroshell 120 SB-C₁₈(50 mm×2.1 mm,2.7 μm)柱,以0.1%甲酸水溶液-0.1%甲酸乙腈溶液为流动相进行定性和定量分析。采用本方法对22种市售蜂蜜进行检测,结果显示8种生物胺在不同的蜂蜜中检出,所有蜂蜜样品中均检测到2-苯乙胺和腐胺,其中2-苯乙胺也是蜂蜜样品中平均含量最多的生物胺。本方法中8种生物胺的线性相关系数均大于0.99,检出限为0.01~0.51 μg/L。在添加水平为100、500、1000 μg/kg时,样品的平均回收率在76%~112%之间,日内精密度小于等于9.8%,日间精密度小于等于13.1%。该方法快速简单,灵敏准确,且回收率稳定,适用于蜂蜜中生物胺的检测。     

固相萃取—超高效液相色谱法测定水产品中6种氟喹诺酮类药物残留

基于固相萃取(SPE)和超高效液相色谱(UPLC)技术,建立可同时测定水产品中诺氟沙星、氧氟沙星、环丙沙星、培氟沙星、洛美沙星、恩诺沙星6种氟喹诺酮类药物残留量的检测方法。经优化后的检测过程及参数为:样品匀浆后以磷酸盐缓冲液为提取剂,提取液经SPE净化、氮吹浓缩后,残渣用0.2%的甲酸水溶液溶解供UPLC分析;选用BEH C18(1.7μm,2.1mm×50 mm)色谱柱,以体积比为937的0.05mol/L柠檬酸+0.1 mol/L乙酸铵缓冲液-乙腈为流动相,流速为0.42mL/min,进样体积为0.2μL,柱温为50℃,荧光检测器检测波长λex=278nm、λem=465nm。该方法简单有效,添加回收率为63.69%～90.83%,最低检出限为0.5～1.8μg/kg,相对标准偏差均低于10%。     

液相色谱-串联质谱法检测饲料中洛美沙星、培氟沙星、氧氟沙星、诺氟沙星残留

目的建立一种可同时检测饲料中4种氟喹诺酮类药物残留的液相色谱-串联质谱(liquid chromatography-tandem mass spectrometry, LC-MS/MS)检测分析方法。方法试样用磷酸盐缓冲液和乙腈混合进行提取, MCX固相萃取柱净化,以甲醇-0.1%甲酸水溶液为流动相, LC-MS/MS法检测,同时定性、定量测定4种氟喹诺酮类抗生素残留。结果 4种氟喹诺酮类抗生素在HypersilGOLDC_(18)色谱柱上分离效果较好,添加的回收率在60.3%～91.0%之间,相对标准偏差在0.87%～5.91%之间(n=6),方法的检测限为2μg/kg,定量限为5μg/kg。结论该方法准确、简便、快速,能满足兽药残留分析的要求,适合测定饲料中4种氟喹诺酮类抗生素残留。     

Qu ECh ERS EMR-Lipid结合LC-MS/MS测定鸡蛋中磺胺类和喹诺酮类药物残留

采用Qu ECh ERS EMR-Lipid技术处理样品,建立快速检测鸡蛋中14种磺胺类药物和16种喹诺酮类药物残留的液质联用检测方法。将鸡蛋样品用2%甲酸乙腈8 mL提取,再加入0.5 mL pH 7.0、0.1 mol/L的EDTA缓冲液震荡,用Qu ECh ERS EMR-Lipid快速样品提取技术净化,最后用0.2%甲酸溶液(A相)和乙腈溶液(B相)作为流动相进行梯度洗脱,采用电喷雾离子源的动态多反应监测模式(dynamic MRM)对30种磺胺类药物和喹诺酮类药物进行定性和定量分析。结果显示,30种抗生素添加水平在8~32μg/kg的回收率为50.09%~102.11%,相对标准偏差小于15.66%,方法检出限为0.00131~0.09717μg/kg。建立的鸡蛋中磺胺类药物和喹诺酮类药物残留检测的检测方法前处理简单易行,便于操作,方法精密度高,可以满足对鸡蛋中磺胺类药物和喹诺酮类药物快速、准确的检测要求,并适合大批量样品的准确定性和定量分析检测。     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status