超高效液相色谱-电喷雾串联质谱测定食品中对位红的检测方法研究

建立了超高效液相色谱-电喷雾串联质谱法测定食品中对位红的检测方法。样品经提取后,采用了Waters Oasis HLB作为固相萃取小柱,进行样品净化,经超高效液相色谱分离后采用电喷雾串联质谱进行定性及定量检测。线性范围为0.1～1.0mg/L,线性相关系数为0.999。方法的定性检出限(S/N=3)为0.26μg/kg,定量检出限(S/N=10)为0.85μg/kg。高、中、低3个浓度水平的加标回收率范围为80.5%～109.5%,相对标准偏差小于10%。     

液相色谱-串联质谱法检测速冻调制肉制品中糖皮质激素类药物残留

建立液相色谱-串联质谱法检测速冻调制肉制品中糖皮质激素类药物残留的方法。样品经乙酸乙酯提取后,过Silica固相萃取柱净化,最后用乙腈定容,经液相色谱-串联质谱仪测定。样品采用外标峰面积法进行定量,该方法的最小检出限量分别为0.2、0.5、1.0μg/kg,定量限分别为0.5、1.0、2.0μg/kg,添加回收率范围为85.0%～96.4%,RSD为2.3%～6.1%。     

固相萃取-超高效液相色谱串联质谱法测定牛奶中6种头孢菌素类抗生素

目的建立固相萃取超高效液相色谱串联质谱(SPE-UPLC-MS/MS)同时检测牛奶中6种头孢菌素类抗生素含量的方法。方法样品经0.05 mol/L的磷酸氢二钾缓冲溶液提取,HLB固相萃取柱净化,液相色谱串联质谱法测定,采用多反应监测模式进行定性和定量分析。结果 6种头孢菌素类抗生素的检出限(S/N=3)和定量限(S/N=10)范围分别为0.05~0.4μg/kg和0.1~1.6μg/kg。样品加标回收率范围为66.3%~110.0%。结论该方法便捷、快速、高效,能够满足牛奶中头孢菌素类抗生素的检测。     

动物肌肉、内脏和牛奶中咪唑脲苯残留量的高效液相色谱测定及液相色谱-串联质谱确证

目的建立固相萃取净化-高效液相色谱和液相色谱-串联质谱测定动物组织和牛奶中咪唑脲苯残留量的分析方法。方法残留的咪唑脲苯采用1%三氟乙酸-乙腈(1:4,v/v)提取,Oasis WCX固相萃取柱净化,高效液相色谱外标法定量,并经液相色谱-串联质谱确证。结果咪唑脲苯检出限为10μg/kg(S/N≥3),定量限为25μg/kg(S/N≥10);在LOQ、MRL和2MRL三个添加水平下重复分析6次,回收率为72.7%~101%,相对标准偏差为1.2%~6.9%。结论该方法稳定、可靠,适用于动物组织和牛奶中咪唑脲苯的测定。     

分散固相萃取-超高效液相色谱-串联质谱测定肉制品中5类药物残留

建立了同时测定肉制品中16种β-激动剂、6种头孢菌素类、6种青霉素类、3种氟喹诺酮类和2种糖肽类药物的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。样品经酶解后,以0.1%甲酸-乙腈(体积分数)提取,分散固相萃取净化,串联质谱ESI正、负模式电离,多反应监测(MRM)模式检测,以保留时间和子离子丰度比定性,外标法定量。结果表明,33种目标物在1.0~300μg/L范围内线性关系良好,相关系数均大于0.996,β-激动剂和氟喹诺酮类药物的方法检出限(LOD,S/N=3)为0.5μg/kg,其他目标物的LOD为3.0μg/kg;加标水平为2.0~100μg/kg时(n=6),平均回收率为74.9%~112%,相对标准偏差为2.2%~10.8%。方法准确、灵敏,适用于肉制品中β-激动剂、头孢菌素类、青霉素类、氟喹诺酮类和糖肽类等药物残留的高通量测定。     

UPLC-MS/MS法分析茶叶中的灭多威农药残留

建立了检测茶叶中灭多威残留的超高效液相色谱-串联质谱(UPLC-MS-MS)分析方法。茶叶样品经乙腈提取,氨基固相萃取柱净化,反相液相色谱对样品进行分离,采用多反应监测模式(MRM)进行定性、定量分析。结果表明:方法检出限为0.5μg/kg,定量限为2.0μg/kg;当添加浓度水平为10、100μg/kg时,加标回收率为71.9%～113.5%,相对标准偏差为5.3%～12.5%。该法灵敏度高、干扰小、定性准确,适用于茶叶中灭多威残留检测,同时可作为液相色谱检测的验证方法。     

固相萃取-液相色谱-串联质谱法检测番茄酱中6种交链孢霉毒素

目的建立固相萃取-液相色谱-串联质谱法检测番茄酱中6种交链孢霉毒素的分析方法。方法番茄酱样品经提取液提取,固相萃取柱净化后,采用液相色谱-串联质谱测定交链孢霉毒素,外标法定量。结果番茄酱样品中交链孢霉毒素添加浓度在2.0～200.0μg/kg时,回收率在66.5%～113.5%之间。检测低限为2.0～50.0μg/kg,相对标准偏差(relative standard deviation, RSD)在2.5%～9.8%。结论该方法简单快速、灵敏度高、定量准确,适合用于番茄酱中6种交链孢霉毒素的检测。     

液相色谱-串联质谱法测定鱼肉中的七种全氟有机物

建立了液相色谱-串联质谱检测鱼肉中七种全氟有机物残留的分析方法。通过优化和比较,样品选用甲醇均质提取,C18固相萃取小柱净化,以乙腈-5mmol/L乙酸铵为流动相经C8反相色谱柱分离后,采用多反应监测(MRM)负离子模式检测。阴性样品添加实验结果表明,特征离子相对强度比值稳定,基质效应干扰少,结合保留时间可实现准确的定性定量,方法检出限为0.01～0.03μg/kg(S/N=3),不同鱼肉基质样本添加水平在0.05～1.0μg/kg时,平均回收率为80.0%～120.0%,相对偏差(n=6)为2.9%～7.6%。     

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。     

液相色谱-串联质谱法测定鸡蛋中的喹诺酮类和四环素类抗生素

应用液相色谱-串联质谱法技术,建立鸡肉中喹诺酮类和四环素类抗生素的检测方法,并对宁夏地区市售鸡蛋进行分析。鸡蛋样品经EDTA-Mcllvaine缓冲溶液超声提取,玻璃纤维滤膜过滤,HLB固相萃取柱净化,乙腈-0.1%甲酸水溶液为流动相,用Waters Atlantis T₃色谱柱分离,以电喷雾正离子模式进行质谱测定。三个加标水平下喹诺酮类抗生素回收率为80.0%~114.0%,相对标准偏差小于12.0%,检出限(S/N=3)为0.2 μg/kg,定量限(S/N=10)为0.8 μg/kg;四环素类抗生素的平均回收率为84.5%~110.0%,相对标准偏差小于12.0%,检出限(S/N=3)为0.2 μg/kg,定量限(S/N=10)为0.8 μg/kg。该方法操作快速简单、重现性好,可用于鸡蛋中喹诺酮类和四环素类抗生素的检测。     

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.     

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