HPLC法同时测定辣椒面中碱性橙2,21,22和酸性橙Ⅱ的含量

建立辣椒面中碱性橙2,21,22和酸性橙Ⅱ的高效液相色谱(HPLC)同时测定的方法。样品经70%乙腈超声提取后离心,采用C18色谱柱分离,以乙腈和10mmol/L乙酸铵水溶液(乙酸0.12%)为流动相进行梯度洗脱,流速为1.0 mL/min,紫外检测器进行检测。结果表明:碱性橙2,21,22在1~9μg/mL和酸性橙Ⅱ在0.1~0.9μg/mL浓度范围内呈现良好的线性关系,样品在添加水平为0.1~0.6mg/kg时,平均回收率为91%~107%,相对标准偏差(RSD)为1.1%~7.8%。该方法具有操作简单、重复性好和准确度高等优点,适用于辣椒面中碱性橙2,21,22和酸性橙Ⅱ的测定。     

超高效液相色谱-串联质谱法测定腐竹中酸性橙Ⅱ和碱性橙

建立了同时检测腐竹中酸性橙Ⅱ和碱性橙2两种非食用色素的高效液相色谱-质谱/质谱测定方法。样品经乙腈-乙酸铵溶液超声提取,经弱阳离子交换固相萃取柱净化后上样。色谱条件采用Waters XBridge C18柱(2.1 mm×150 mm,5μm),流动相为0.1%甲酸-5 mmol/L乙酸铵水溶液:乙腈梯度洗脱,流速为0.3 mL/min,柱温40℃,酸性橙Ⅱ和碱性橙2分别采用电喷雾负离子和正离子扫描模式。该方法2种物质检出限均为1.0μg/kg,定量限均为3.0μg/kg,线性范围:0-20ng/mL。加标回收率:酸性橙Ⅱ为92.4-95.9%;碱性橙2为90.2-96.9%。该方法操作简单高效,重现性较好,适用于腐竹中2种非食用色素的含量测定。     

液相色谱串联质谱法检测鲍鱼汁中的酸性橙Ⅱ

目的建立了液相色谱/串联质谱(HPLC-MS/MS)测定鲍鱼汁中酸性橙Ⅱ的方法,并用于实际样品的分析。方法样品经甲醇+乙酸铵溶液(体积比为1+1)振荡提取后用OASISWAXSPE柱净化,以乙腈-乙酸铵缓冲溶液为流动相,在C18色谱柱(2.1mm×50mm,1.7μm)上经梯度洗脱分离后以多反应监测质谱测定(m/z326.9→170.8,326.9→155.8)。结果方法的最低定量浓度(LOQ)为0.1mg/kg,5和50mg/kg两个水平加标样的平均回收率分别为87.0%和101.0%,线性相关系数为0.999,线性范围为10～5000μg/L。对14份食品专项整治抽检样品进行分析检测,其中7份检出酸性橙Ⅱ,其含量范围为1.2～73.8mg/kg。结论该方法能够满足鲍鱼汁中酸性橙Ⅱ的测定要求。     

LC-MS/MS测定黄鱼中碱性嫩黄O及酸性橙Ⅱ

建立高效液相色谱-串联四极杆质谱正负离子切换模式同时快速测定黄鱼中黄色工业染料碱性嫩黄O及酸性橙Ⅱ的检测方法。样品匀质后,经乙腈提取,盐析,-20℃冷冻脱脂,低温离心后,取乙腈层采用高效液相色谱-串联质谱法分离、测定。结果表明碱性嫩黄O在0.5μg/kg~10μg/kg、酸性橙Ⅱ在5μg/kg~100μg/kg范围内呈良好的线性关系,高中低浓度回收率在70%~110%,相对标准偏差(n=5)小于15%,碱性嫩黄O、酸性橙Ⅱ检出限分别为0.5、5μg/kg。本方法适用于黄鱼中违禁工业染料碱性嫩黄O及酸性橙Ⅱ的测定。     

高效液相色谱法同时测定食品中18种食品添加剂

建立高效液相色谱同时测定食品中18种食品添加剂的高通量分析方法。对于不含油脂或油脂含量低的样品采用含抗坏血酸棕榈酸酯的正己烷饱和乙腈-6mol/L HCl溶液-饱和氯化钠混合溶液一次提取净化,对于油脂样品采用含抗坏血酸棕榈酸酯的正己烷饱和乙腈-乙腈饱和正己烷液液萃取。采用Ecosil C18色谱柱(250mm×4.6mm,5μm),乙腈-0.6%乙酸溶液作为流动相,梯度洗脱,用紫外检测器检测,检测波长280nm,外标法峰面积定量。18种食品添加剂在1.0～25mg/L范围内线性良好,相关系数r均大于0.99,样品在10、25mg/kg和50mg/kg三个添加水平的平均回收率为88.9%～99.9%之间,相对标准偏差为2.43%～11.7%(n=6),方法的定量限为10mg/kg。方法简便、准确,适用于食品中18种食品添加剂高通量的检测。     

超高效液相色谱-电喷雾串联质谱法同时测定调味品与熟肉制品中6种工业染料

建立了超高效液相色谱-电喷雾串联质谱法(UPLC-MS/MS)测定调味品与熟肉制品中碱性橙Ⅱ、碱性橙21、碱性橙22、酸性橙Ⅱ、酸性红1号和碱性玫瑰精6种工业染料分析方法。样品用V(乙腈)∶V(水)7∶3的溶液提取,取上清液过滤,以BEH C18柱(1.7μm,2.1×50 mm)为分离柱,甲醇和10mmol/L乙酸铵(含0.1%甲酸)梯度洗脱,在优化的实验条件下,碱性橙Ⅱ、碱性橙21、碱性橙22、酸性橙Ⅱ和碱性玫瑰精的检出限均为0.5μg/kg,定量限为1μg/kg;酸性红1号检出限为50μg/kg,定量限为100μg/kg;碱性橙Ⅱ、碱性橙21、碱性橙22、酸性橙Ⅱ和碱性玫瑰精的线性范围为1~50μg/kg,相关系数均大于0.99。酸性红1号的线性范围为50~1000μg/kg,相关系数大于0.99。样品在三个添加水平下平均回收率在75.6%~99.7%之间,相对标准偏差在0.9%~10.7%。可用于调味品与熟肉制品中6种工业染料的检测。     

食品中黄曲霉毒素B_1的液相色谱-串联质谱测定法

建立了食品中黄曲霉毒素B1残留量的超高效液相色谱-串联质谱的检测方法。样品经乙腈+水(84+16)提取后,经多功能净化柱净化,超高效液相色谱-串联质谱法检测。本方法定量限为1μg/kg,线性范围为1~20 ng/mL;在黄曲霉毒素B1添加水平为1~10μg/kg时,在玉米样品中的回收率为95%~105%;在酱油样品中的回收率为96%~106%。     

高效液相色谱法测定酱卤肉中酸性橙Ⅱ的优化

目的 建立一种酱卤肉中酸性橙Ⅱ的液相色谱-多波长扫描(HPLC-DAD)检测方法。方法 样品经氨水甲醇提取液提取, 调节pH沉淀蛋白后, 过混合弱阴离子(PWAX)固相萃取柱净化。采用20mM乙酸铵(A)和甲醇(B)作为流动相进行等度洗脱,采用DAD对酸性橙Ⅱ进行多波长检测。结果 本方法在10 min内完成目标化合物与杂质的分离。酸性橙Ⅱ在0.1、0.5和2.0 mg/kg添加水平的回收率为76.0%~92.5%, 相对标准偏差小于15%(n=6), 方法定量限为0.1 mg/kg。结论 该方法快速、准确、灵敏, 适合酱卤肉等蛋白质含量高的样品中酸性橙Ⅱ的检测。     

超高效液相色谱-串联质谱法同时测定小吃类食品和火锅底料中5种罂粟壳生物碱和6种工业染料

目的建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)同时测定小吃类食品及火锅底料中5种罂粟壳生物碱和6种工业染料。方法样品采用乙腈溶液提取,乙腈层经无水硫酸镁脱水后于40℃下旋转蒸发浓缩至干,用2.0 mL乙腈+0.1%甲酸水(95:5,V:V)溶解残渣,样液过膜后经C_(18)柱分离,电喷雾正、负离子同时扫描模式下多反应监测方式检测,外标法定量。结果 5种罂粟壳生物碱和6种工业染料在2.5~100μg/L的浓度范围内,具有良好的线性关系(相关系数均大于0.9980),在3个添加水平下样品的平均回收率为72.2%~108%,相对标准偏差2.5%~9.6%,罂粟碱、那可丁、蒂巴因、玫瑰红B、酸性橙Ⅱ、碱性嫩黄O、碱性黄1的检出限为1.0μg/kg,吗啡、可待因、碱性橙Ⅱ、苏丹红Ⅳ的检出限为2.5μg/kg。实际样品检测中,检出酸性橙Ⅱ阳性样品6个,含量为0.00706~74.2 mg/kg。结论该方法准确、灵敏、快速,是同时检测小吃类食品和火锅底料中罂粟壳生物碱和工业染料的有效方法。     

HPLC同时检测酸性橙Ⅱ和碱性嫩黄O色谱条件优化

该研究建立高效液相色谱法同时检测食品中酸性橙Ⅱ和碱性嫩黄O的方法,对高效液相色谱中色谱柱、柱温、流动相种类及比例、流速、波长等影响因素进行了研究及优化,得到色谱检测条件为：色谱柱为Kromasil C18（4.6 mm×150 mm,5 μm）;流动相为甲醇-50 mmol/L乙酸铵溶液=50∶50(V/V);流速：1.0 mL/min;检测波长450 nm;柱温35 ℃。在此最佳条件下,碱性嫩黄O及酸性橙Ⅱ的分离度好,且峰型正常。结果表明,该方法适合食品中碱性嫩黄O及酸性橙Ⅱ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