超高效液相色谱-串联四极杆质谱结合分散固相萃取技术测定禽蛋中五氯苯酚残留量

目的 建立分散固相萃取结合超高效液相色谱-串联四级杆质谱技术测定禽蛋中五氯苯酚残留量的分析方法。方法 取均质后的禽蛋样品经乙腈溶液提取, 加入无水硫酸镁和氯化钠进行脱水和盐析,高速离心分层后, 取适量乙腈层溶液经0.1%(V:V)甲酸稀释后, 用酸性氧化铝粉末进行样品净化并以10000 r/min离心取上清液, 过0.22 μm滤膜后上机测定。使用反相色谱柱进行分离, 流动相为乙腈：0.1%甲酸=65:35, 采用等度程序进行洗脱, 串联四级杆质谱进行定性定量分析。结果 五氯苯酚在5~250 μg/kg范围内线性关系良好(r>0.995), 方法的最低检出限为2.5 μg/kg, 最低定量限为5 μg/kg, 添加回收率在74.44%~91.91%, 相对标准偏差(relative standard deviation, RSD)＜10%。结论 该方法具有较好的准确度与精密度, 适用于禽蛋中五氯苯酚残留量的测定。     

液相色谱-串联四极杆质谱法测定鸡蛋中8种三唑类农药残留量

目的建立液相色谱-串联四极杆质谱法测定鸡蛋中丙环唑、三唑酮、烯唑醇、抑霉唑、三唑醇、戊唑醇、氟硅唑和三环唑残留量的分析方法。方法取均质后的鸡蛋样品经乙腈溶液提取,加入无水硫酸镁和氯化钠进行脱水和盐析,高速离心后,取适量上层提取液经0.1%(V:V)甲酸稀释后,用中性氧化铝粉末净化并以10000 r/min离心取上清液,过0.22μm滤膜后上机测定。使用反相色谱柱进行分离,流动相为0.1%甲酸与乙腈,采用梯度程序进行洗脱,串联四极杆质谱法进行定性定量分析。结果 8种农药在2.5~250μg/kg范围内线性关系良好(r≥0.995),方法的检出限为1μg/kg,定量限为2.5μg/kg,添加回收率在78.31%~88.53%内,相对标准偏差低于10%。结论该方法具有较好的准确度与精密度,适用于鸡蛋中丙环唑、三唑酮、烯唑醇、抑霉唑、三唑醇、戊唑醇、氟硅唑和三环唑的残留量测定。     

液相色谱串联质谱法快速测定鱼肉中四聚乙醛残留量

建立测定鱼肉中四聚乙醛残留量的液相色谱串联质谱分析方法。样品经乙腈提取,提取液经盐析后采用N-丙基乙二胺和C18填料净化,净化液经0.1%甲酸溶液稀释后进样分析。分析时采用Acquity BEH C18,以0.1%甲酸溶液和乙腈作为流动相作梯度洗脱,电喷雾正电子(ESI+)模式电离,多反应监测(MRM)模式检测,内标法校准进行定量。四聚乙醛在0.05~5.0μg/L质量浓度范围内呈良好的线性,线性相关系数大于0.999,鱼肉样品中最低定量限为1.0μg/kg。鱼肉样品中添加1.0~2.0μg/kg的回收率在98.5%~100.8%之间,相对标准偏差均小于10%。     

亲水作用色谱柱-高效液相色谱法测定鸡蛋中氨丙啉的残留量

目的建立亲水作用色谱柱-高效液相色谱法检测鸡蛋中氨丙啉残留的分析方法。方法样品加入10 mL5%三氯乙酸水溶液进行提取,离心后取一半上清液过HLB柱净化。色谱柱为Poroshell 120 HILIC-Z (100 mm×3.0 mm, 2.7μm),流动相为5 mmol/L乙酸铵-0.1%甲酸水溶液和乙腈,等度洗脱, 5 mmol/L乙酸铵-0.1%甲酸水溶液:乙腈=20:80(V:V),流速为0.4 mL/min,进样量为20μL,检测波长267 nm。结果氨丙啉在0.35～10.0μg/mL呈良好的线性关系, r大于0.999。方法的最低定量限为250μg/kg。氨丙啉在250～2000μg/kg的浓度添加水平上,其回收率在85.0%～96.7%,批内、批间的相对标准偏差小于6%。结论该方法具有简便快捷、灵敏度高等特点,适用于鸡蛋中氨丙啉的残留检测。     

液相色谱串联质谱法快速测定动物组织中克百威及其代谢产物残留量

建立快速测定动物组织中克百威及其代谢产物三羟基克百威残留量的液相色谱串联质谱(liquid chromatography?with?tandem?mass spectrometry,LC-MS/MS)分析方法。动物组织样品中残留物利用乙腈提取,提取后溶液经N-丙基乙二胺(primary secondary amine,PSA)和C18材料净化,净化后的提取液经氮吹后用0.1%甲酸溶液-乙腈(50∶50,V/V)溶解,进行LC-MS/MS分析。采用Acquity BEH C18色谱柱分离,用0.1%甲酸溶液-乙腈作为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,多反应监测(multiple reaction monitoring,MRM)模式检测,内标法定量。克百威和三羟基克百威分别在0.05~25.0μg/L和0.25~50.0μg/L质量浓度范围内具有良好的线性关系,线性相关系数均大于0.999;在动物组织(猪肉和牛肉)中克百威和三羟基克百威的方法检测限分别为0.10μg/kg和0.50μg/kg,定量限分别为0.25μg/kg和1.0μg/kg。添加范围为0.25~10μg/kg时,平均回收率在95.7%~107.0%之间,批内相对标准偏差(relative standard deviation,RSD)在3.2%~5.9%之间,批间RSD在4.5%~6.6%之间。该方法能满足动物肉组织中克百威及其代谢产物残留量快速分析的要求。     

超高效液相色谱质谱法快速检测动物源性食品中的四种兽药残留

建立了采用超高效液相色谱串联质谱仪快速检测动物组织中甲氧苄胺嘧啶、克林霉素、泰妙菌素和吡喹酮四种药物残留的分析方法。动物组织样品经乙腈提取后,用正己烷去除脂肪等杂质,Waters Acquily UPLC BEH C18色谱柱分离,以乙腈和0.1%甲酸水溶液为流动相进行梯度洗脱,电喷雾正离子(ESI+)模式电离,液相色谱-质谱法(UPLC-MS/MS)测定。结果表明:4种药物在2.5～200μg/L范围内呈现良好的线性关系,相关系数R2均大于0.996,在此范围内添加回收率为65.8%~95.9%,相对标准偏差为3.2%~13.1%,定量下限为0.5μg/kg。     

液相色谱-串质谱法测定大米中异噁唑草酮及代谢物残留量

目的建立大米中异噁唑草酮及代谢物残留量的液相色谱-串联质谱法测定方法。方法试样中残留的异噁唑草酮除草剂及代谢物用乙酸乙腈溶液(1:99,V:V)高速匀浆提取,提取液经N-丙基乙二胺(PSA)、十八烷基硅烷(ODS)净化,经色谱柱为ACQUITY UPLC BEH Phenyl分离和流动相为1.5%乙酸的乙酸铵(1mmol/L)-乙腈进行梯度洗脱,用配有大气压化学电离源(APCI)的液相色谱-串联质谱仪检测和确证。结果异噁唑草酮及代谢物在0.0025~1.000μg/m L浓度范围内呈现良好线性关系(r=0.9998~0.9999)。当样品加标浓度在5~200μg/kg范围内时,其样品加标平均回收率为70.2%~110.6%,相对标准偏差为7.38%~12.84%。异噁唑草酮及代谢物的最低检出限分别为10μg/kg、5μg/kg。结论本方法适用于大米中异噁唑草酮及代谢物残留的同时测定。     

多壁碳纳米管分散固相萃取结合LC-MS-MS测定鸡肉中金刚烷胺

建立了采用多壁碳纳米管为吸附剂的分散固相萃取净化、液相色谱串联质谱测定鸡肉中金刚烷胺残留量的方法。鸡肉样品经乙酸乙腈提取后,调节pH值至11,加入75 mg多壁碳纳米管进行分散固相萃取,被吸附的药物经5.0%甲酸溶液:甲醇(5∶5,V/V)洗脱,洗脱液过滤膜后直接进样分析。采用Acquity UPLC BEH C18色谱柱分离,以0.1%甲酸水溶液和甲醇作为流动相作梯度洗脱,电喷雾正电子(ESI+)模式电离,多反应监测模式检测,内标法校准进行定量。金刚烷胺在0.05~5.0μg/L质量浓度范围内呈良好的线性,线性相关系数均大于0.99,鸡肉样品中最低定量限为0.50μg/kg。鸡肉样品中添加0.5~1.0μg/kg金刚烷胺的回收率在97.8%~103.6%之间,相对标准偏差均小于10%。     

液相色谱-串联质谱法测定肉制品中的氟尼辛葡甲胺

通过试验确定了肉制品中氟尼辛葡甲胺的前处理方法及液相色谱-串联质谱法(LC-MS/MS)测定条件。样品经过乙腈-乙酸乙酯(1∶1,V/V)超声提取,PCX固相萃取柱净化,采用C18(2.1×100mm,3.5μm)柱分离,以0.1%甲酸水溶液和0.1%甲酸乙腈溶液作为流动相梯度洗脱,采用电喷雾离子源,多反应监测方式进行采集,外标法定量。结果表明:氟尼辛葡甲胺在0.1~50ng/mL质量浓度范围内呈现良好的线性关系,标准曲线相关系数r2=0.9998,方法回收率为85.0%~110.0%,相对标准偏差(RSD)6.0%;方法最低检出限为0.1μg/kg,定量限为0.3μg/kg。该方法操作简单,易于推广,可以对肉制品中氟尼辛葡甲胺进行准确的定性和定量测定。     

超高效液相色谱-串联质谱法同时检测牛乳中4 种驱虫药物残留

建立同时检测牛乳中4 种驱虫药物（吡喹酮、伊维菌素、阿维菌素、多拉菌素）残留的超高效液相色谱-串联质谱的方法。样品经乙腈提取,碱性氧化铝固相萃取小柱净化,采用UPLC ACQUITY BEH C18柱,以0.1%甲酸-乙腈（A）和0.1%甲酸-5.0 mmol/L乙酸铵（B）为流动相,梯度洗脱分离,在电喷雾正离子模式下以多反应监测方式检测。结果表明：4 种驱虫药物在5～100 ng/mL范围内线性良好,相关系数大于0.996,加标样品的平均回收率为76.4%～113.3%,相对标准偏差（n=6）为2.4%～10.6%。吡喹酮、伊维菌素、阿维菌素、多拉菌素的检出限分别为1.0、2.5、2.5、2.5 μg/kg。该方法简便、快速、准确,可以同时检测牛乳中吡喹酮、伊维菌素、阿维菌素、多拉菌素残留。     

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