全自动免疫亲和在线净化—高效液相色谱法快速测定粮食中赭曲霉毒素A

建立了全自动免疫亲和在线净化-高效液相色谱法快速测定粮食中赭曲霉毒素A(Ochtatoxin A,OTA)的方法。玉米、小麦样品经乙腈-水(60:40,V:V)提取,3%Tween-20(m/V)水溶液10倍稀释后,用自动进样器注入RIDA~? REST在线固相萃取系统,经赭曲霉毒素A免疫亲和小柱净化后,以乙腈-2%乙酸水(50:50,V:V)为流动相,流速为1.0 mL/min,C18色谱柱(150 mm×3.5 mm,3.5μm)分离,荧光检测器测定。根据3倍信噪比的峰响应值,确定赭曲霉毒素A的检出限为0.24μg/kg,在0.012 5～0.5μg/L范围内呈线性相关,R~2值为0.999 8;在玉米、小麦样品中加标回收率为80.1%～106.9%,变异系数为2.4%～8.2%。本方法一次装柱可检测60个样品,24 h可检测100个样品,满足谷物中赭曲霉毒素A快速准确定量检测的需要。     

高效液相色谱-串联质谱法测定多种食品和饲料中的胶霉毒素

建立了加压溶剂萃取结合全自动固相萃取技术-高效液相色谱-串联质谱法(high performance liquid chromatography-mass spectrometry,HPLC-MS/MS)测定玉米和小麦等禾谷食品、猪的肌肉和肝脏等动物源食品及猪和鸡的饲料中胶霉毒素的液相色谱串联质谱法。前处理时依次采用加压溶剂萃取(pressurized liquid extraction,PLE)和全自动固相萃取(automated solid phase extraction,ASPE)技术,乙腈/水(50/50,V/V)为玉米、小麦及饲料样品的加压溶剂萃取液,乙腈/正己烷(60/40,V/V)为猪的肌肉和肝脏样品的加压溶剂萃取液,甲醇/水(85/15,V/V)为所有样品的全自动固相萃取洗脱液。HPLC-MS/MS检测,基质匹配工作曲线外标法定量。结果表明,不同样品中胶霉毒素在0.2~100μg/L范围内具有良好的线性关系,相关系数R2≥0.995 8;不同样品中的胶霉毒素最低检出限在0.09~0.15μg/kg,最低定量限在0.23~0.31μg/kg;添加不同浓度水平的胶霉毒素,平均回收率为81.8%~95.4%,变异系数≤13.2%。     

在线固相萃取-液相色谱-串联质谱法快速测定玉米粉和面粉中伏马毒素

建立在线固相萃取-液相色谱-串联质谱法检测玉米粉和面粉中3种伏马毒素的分析方法。样品用乙腈-水(50∶50,V/V)提取,提取液直接上样,经过WAX在线固相萃取柱净化,以0.1%甲酸溶液和乙腈为流动相,经XBridge C_(18)色谱柱分离,采用电喷雾正电离多反应模式监测,内标法定量。结果表明:伏马毒素B1、伏马毒素B2和伏马毒素B3在0.05~50 ng/m L之间线性关系良好,相关系数均大于0.999 0;检出限和定量限分别为0.08μg/kg和0.2μg/kg;添加水平为0.2~50.0μg/kg时,方法回收率范围为93.9%~117.8%,相对标准偏差范围在1.8%~9.4%。此方法简便快速、灵敏度高,可用于玉米粉和面粉中伏马毒素的准确定量。     

高效液相色谱法测定食品中苏丹红Ⅰ~Ⅳ

目的建立准确可靠的高效液相色谱法测定食品中苏丹红I~IV的方法。方法用乙腈提取样品中的苏丹红,经漩涡超声离心后,将乙腈层倾倒出,用乙腈重复提取,通过凝胶色谱的净化,用液相色谱进行检测。其中凝胶色谱柱为Bio-BeadsTM S-X3 Beads,液相色谱柱为Waters C18(4.6 mm×150 mm,5μm),液相色谱流动相为乙腈-水(V:V,90:10)。结果 4种苏丹红染料的检出限均能达到10μg/kg,满足国标要求。标准加入量为0.16μg/m L浓度时,辣椒粉的回收率为92.5%~97.5%、辣椒酱的回收率为83.8%~87.5%、香肠的回收率为82.5%~98.8%,相关系数0.9995以上,且重复性良好。结论高效液相色谱法可以测定食品中苏丹红I~IV,适用于批量样品的检测。     

固相萃取-高效液相法测定芝麻油中苯并(a)芘

建立一种快速、高效测定芝麻油中苯并(a)芘的固相萃取-高效液相色谱(SPE-HPLC)方法。样品前处理采用硅胶固相萃取柱串联氧化铝固相萃取小柱,稀释液和淋洗液选择正己烷,洗脱液选择二氯甲烷,在40℃下氮吹干后,乙腈复溶后检测。采用Waters RP C18色谱柱(4.6 mm×250 mm,5μm)分离,以乙腈-水(90∶10)作为流动相,用荧光检测器检测,外标法峰面积定量。结果表明,苯并(a)芘在1.00 ng/m L~20.00 ng/m L浓度范围内线性良好,相关系数r2为0.999 8,检出限为0.05μg/kg,定量限为0.16μg/kg,加标回收率达到92.2%~98.5%。     

固相萃取-超高效液相色谱法检测榨菜中氯吡苯脲的研究

建立了固相萃取-超高效液相色谱法定榨菜中氯吡苯脲的方法。样品匀浆后经乙腈提取,固相萃取柱净化后,在流动相为乙腈-纯水(体积比65∶35)、紫外检测波长为260 nm的色谱条件下进行分离检测。结果表明:丙基乙二胺PSA分散固相萃取柱对样品净化效果好,氯吡苯脲在0.1~10.0μg/m L范围内线性关系良好,相关系数r=0.9993,方法检出限为0.03 mg/kg,试样在0.1~1.0 mg/kg添加水平下的平均回收率在96.3%~103.2%之间,RSD值在0.4%~2.2%之间。结论:方法准确度较好,操作简单快捷,样品净化效果好,测定低限能满足限量要求。     

固相萃取–液相色谱–荧光检测法测定半夏中 苯并[a]芘残留量

目的建立半夏样品中苯并[a]芘残留量的固相萃取-液相色谱-荧光检测法。方法样品用水浸泡后,用正己烷萃取,硅胶固相萃取柱和ENV固相萃取柱净化,分析时采用SUPELCOSILTM LC-PAH(25 cm×4.6 mm,5μm)色谱柱分离,以乙腈-水(85:15=V:V)为流动相,荧光检测激发波长384 nm,发射波长406 nm,外标法定量。结果苯并[a]芘的检出限为0.1μg/kg,在1.0~50.0 ng/m L浓度范围内,苯并[a]芘的线性相关系数为0.9999,线性关系良好,方法回收率在78.0%~102.5%范围内,相对标准偏差低于9.6%。结论该方法准确、实用、简便、快速,在中药材的苯并[a]芘残留量检测方面有广泛应用前景。     

分散固相萃取-高效液相色谱法测定水果中三氯生及三氯卡班

目的建立分散固相萃取-高效液相色谱法测定水果中三氯生及三氯卡班残留的新方法。方法样品采用乙腈溶液涡旋超声提取后,加入十八烷基键合硅胶吸附剂(C18)作为分散固相萃取净化剂进行净化(200mg),用高效液相色谱法在278 nm处测定,采用PICKERING C8色谱柱(4.6 mm×250 mm i.d.,5μm),以甲醇:水(78:22,V:V)的溶液为流动相等度洗脱,流速1.2 m L/min。结果在最优检测条件下,各目标化合物的加标回收率为72.9%~104.4%,相对标准偏差在2.1%~9.1%之间。三氯生及三氯卡班的检出限分别为0.05和0.02 mg/kg,定量限分别为0.15和0.06 mg/kg。结论该方法分析快速、简便,适用于水果中三氯生及三氯卡班的测定。     

固相萃取-高效液相色谱荧光法测定水果中1-萘乙酸残留量

建立了固相萃取-高效液相色谱荧光法测定水果中1-萘乙酸(NAA)残留量的方法。样品经乙腈提取,氨基固相萃取小柱净化,用高效液相色谱荧光检测器测定。经过验证,方法定量限为0.002 mg/kg,当水果中添加NAA水平为0.004、0.04、0.4 mg/kg时,回收率为82.1%~114.1%之间,相对标准偏差(RSD)为0.6%~10.5%。该方法准确度好、灵敏度高,适合水果中NAA残留量的测定。     

液相色谱串联质谱法测定热加工食品中杂环胺

建立固相萃取-超高效液相色谱-串联质谱法同时测定热加工食品中14 HAAs种含量的方法。样品经过5%盐酸-甲醇酸化后均质,涡旋,超声提取,经混合型弱阳离子交换PCX固相萃取小柱富集、净化,5%氨水/甲醇溶液洗脱,采用BEH C18色谱柱,以3%甲酸和乙腈为流动相进行梯度洗脱分离,电喷雾离子正源模式(ESI+),采用多反应监测(MRM)扫描,以内标法定量分析,结果表明,14种HAAs在1.25μg/kg~25μg/kg范围内线性关系良好,相关系数r0.99;在12 min内实现分离,加标回收率在51.1%~118.5%之间,相对标准差(RSD%)在0.9%~9.6%之间;检出限(LOD)在0.08μg/kg~1.1μg/kg之间。该方法简便快捷,易于实现大规模在线分析。     

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