HPLC法同时测定植物样品中3种甾醇含量

建立高效液相色谱法(HPLC)同时测定植物样品中麦角甾醇、胆甾醇和豆甾醇的方法。样品经皂化、萃取后,用紫外检测器进行测定。优化后的色谱条件为:Shim-pack CLC ODS色谱柱(250 mm×4.6 mm, 5.0μm);流动相采用纯甲醇;检测波长205 nm和282 nm,流速1.0 mL/min;柱温35℃;进样量10μL。检测方法显示, 3种甾醇在1.00～200 mg/L的线性范围内相关系数R~20.999,方法精密度RSD0.5%(N=6),在加标浓度为20.0～200 mg/kg条件下,加标回收率93.6%～103.4%(N=6),检出限(S/N=3) 3.0～6.0 mg/kg,定量限(S/N=10) 10～20 mg/kg。     

用高效液相色谱法同时测定葡萄酒中4种色素含量方法的研究

为了建立同时测定葡萄酒中喹啉黄、坚牢绿、偶氮玉红（又名酸性红,二蓝光酸性红）和专利蓝等4种色素含量的高效液相色谱方法,采用样品除去乙醇,经水提取和过滤后,使用C18色谱柱（4．6×250mm,5μm）分离,以甲醇和乙酸铵（0．02mol／L）为流动相梯度洗脱,流速为1．0mL／min,二极管阵列检测器检测,波长410nm,柱温30℃。结果显示：4种色素的工作曲线在1．0～50．0μg／mL范围内浓度与峰面积呈良好的线性关系,相关系数r均〉0．999。以S／N=3确定各检出限：喹啉黄为0．23mg／kg,坚牢绿为0．37mg／kg,偶氮玉红为0．29mg／kg,专利蓝为0．15mg／kg。精密度（RSD,n=6）〈3．0％。回收率在91．5％～100．8％。说明该方法干扰小,灵敏度高,分离效果好,操作简便、快速和准确可靠。     

高效液相色谱法同时测定食品中7种合成色素

建立了食品中柠檬黄、新红、苋菜红、胭脂红、日落黄、诱惑红和赤藓红7种合成色素的高效液相色谱分析法。样品经含有1%氨水的70%乙醇提取,聚酰胺粉末吸附、净化和富集后进行HPLC分析。采用Eclipse plus C18（250 mm×4.6 mn,5μm）色谱柱为分析柱,0.02 mmol/L乙酸铵水溶液-甲醇为流动相梯度洗脱,二极管阵检测器检测,外标法定量。结果表明：7种色素在0.5~20.0mg/L范围内有良好的线性关系,方法的检出限（S/N=3）分别为0.05、0.05、0.03、0.03、0.05、0.06和0.07 mg/kg,加标回收率为82.83%~105.39%,相对标准偏差不大于8.40%。     

超高效液相色谱法同时测定酱腌菜中的九种防腐甜味剂

目的 建立了采用超高效液相色谱（UPLC）-二极管阵列检测器（PDA）同时快速检测酱腌菜中七种防腐剂（山梨酸、苯甲酸、脱氢乙酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯）和两种甜味剂（糖精钠、安赛蜜）的方法。方法 采用Waters ACQUITY UPLC BEH C18色谱柱(2.1?00mm,1.7μm),流动相为用甲醇 0.02mol/L乙酸铵溶液,梯度洗脱,在35℃柱温,0.20 mL/min流速下,采用二极管阵列检测器在230、257 nm波长处进行检测,外标法定量。结果 2种甜味剂和7种防腐剂15 min内完全分离,在10～250 mg/L范围内,峰面积和质量浓度的线性关系良好（r≥0.9991）,以3组高、中、低浓度作为不同的添加水平,平均加标回收率为85.1%～98.8%,RSD为3.5%～8.5%(n=6),检出限（S/N=3）为0.2～1.0 mg/kg,定量限（S/N=10）为0.5～4.0 mg/kg。结论 本方法操作方便、分离效果好、线性范围宽,能满足酱腌菜中7种防腐剂和2种甜味剂的检测要求。     

涤纶中致癌芳香胺的加速溶剂萃取－UPLC-MS/MS快速测定

利用加速溶剂萃取结合超高效液相色谱-串联质谱（UPLC-MS∕MS）技术,建立了一种能在6min内快速分离和测定涤纶中禁用偶氮染色剂可分解出的22种致癌芳香胺的方法。样品经丙酮加速溶剂萃取、浓缩,再经氧化-还原裂解反应,用乙酸乙酯萃取反应液中的芳香胺,再将萃取液用N2吹至近干,用甲醇-水溶液（1∶9,v∶v）溶解定容,采用Acquity UPLC BEH C18柱（100 mm × 2.1 mm,1.7 μm）分离,以甲醇-0.05%甲酸溶液为流动相,梯度洗脱,电喷雾正离子模式多反应监测,外标法定量。该方法在0.01～0.2 μg/mL范围内线性关系良好（γ＞0.99）,在添加浓度为15 ～ 30 mg/kg水平内,平均回收率范围为33.28 ± 1.83～ 107.14 ± 1.10 ％,相对标准偏差（RSD）为0.38 ～ 10.9％,方法检出限（LOD）为0.96 ～ 17 μg/kg,方法定量限（LOQ）为3.2 ～ 56.1 μg/kg。本方法样品前处理自动化程度高,操作过程简便快速,重复性好,能满足涤纶中的可分解出致癌芳香胺的禁用偶氮染色剂的快速筛选与测定。     

高效液相色谱-二极管阵列检测器同时测定糕点中糖精钠和脱氢乙酸的方法研究

建立了糕点中糖精钠和脱氢乙酸同时测定的高效液相色谱法。糕点样品经氢氧化钠、硫酸锌沉淀后,以甲醇-10mmol/L醋酸铵(PH=5.5)为流动相,梯度洗脱,经AtlantisT3C18色谱柱分离,二极管阵列检测器检测,外标法定量。结果表明:在0.4～50μg/mL浓度范围内,两种物质线性关系良好,线性相关系数均大于0.9999。在5mg/kg、10mg/kg、50mg/kg三个浓度加标水平下,糖精钠和脱氢乙酸的回收率分别为85.0%～101.2%和87.3%～97.9%,相对标准偏差均小于10%。该方法操作简单、快速、准确,能满足复杂糕点基质中两种化合物同时测定的要求。     

液相色谱仪测定配制酒中苋菜红的方法研究

方法：利用液相色谱仪（DAD检测器）,对配制酒中的苋菜红做色剂进行检测,将样品进行加热超声除醇,再经过p H=6.0的乙醇氨水反复提取出来,经过PA SPE净化柱利用固相萃取装置萃取净化,最后经过氮吹浓缩、流动相乙酸铵（20 mmol/L）复溶后,过0.22μm滤膜上机检测。结果：本方法按信噪比方式确定检出限（S/N≥3）为0.5 mg/kg;线性范围为0.5μg/m L～5.0μg/m L,线性相关系数为0.998;重复性和再现性相对偏差0.37%～2.97%(n=6);样品加标浓度分别为1.0 mg/kg、2.5 mg/kg和4.5 mg/kg,样品加标回收率在89%～114%范围之间。结论：本方法优化了前处理损失大的问题,且前处理后样品基质干扰小,灵敏度高,适用于配制酒中苋菜红的快速检测。     

基质固相分散-高效液相色谱法测定川味香肠中的苏丹红染料

建立了川味香肠中苏丹红I～IV的基质固相分散(MSPD)-高效液相色谱(HPLC)分析方法。样品以无水硫酸钠作为分散基体,研磨均匀后与中性氧化铝同时装柱,正己烷淋洗净化,以丙酮-正己烷(5∶95,V/V)溶液洗脱。用InertsilODS-spC18柱(4.6mm×250mm,5μm)进行分离,流动相A为含0.1%甲酸的甲醇,流动相B为0.02mol/L的乙酸铵溶液(A∶B=85∶15,V/V),等度洗脱,柱温40℃。二极管阵列检测器检测,检测波长为490nm,利用保留时间和光谱图定性,外标法定量。4种苏丹红染料在0.10～50.00μg/mL范围内线性关系良好,相关系数均大于0.9999,苏丹红I、II、III、IV的检出限(LOD)分别为0.008～0.011mg/kg(信噪比S/N=3)。在添加浓度为5.0～25.0mg/kg范围内平均回收率达85.54%～94.66%,相对标准偏差(RSD)为0.87%～4.23%(n=6)。     

高效液相色谱法测定纺织品中喹啉的含量

文章建立了一种测定纺织品中喹啉的液相色谱(HPLC)分析方法。方法以甲醇超声提取样品,C18色谱柱分离,流动相为甲醇/水(60∶40,v∶v),检测波长为225 nm。实验结果表明,该方法定量限(S/N=10)为3.0 mg/kg,在3.0、6.0、30.0 mg/kg添加水平下的回收率为82.5%～99.9%,相对标准偏差为1.9%～6.1%。该方法快速简便,回收率高,精密度好,能够满足纺织品中喹啉的检测要求。     

高效液相色谱法测定糕点中5种食品添加剂

建立糕点中常用的3种防腐剂和2种甜味剂的高效液相色谱(HPLC)分析方法。样品以中性氧化铝作为分散基体,研磨均匀后用甲醇—水(70∶30,体积比)进行超声波提取I,nertsil ODS-sp C18柱(4.6 mm×250 mm,5μm)分离。流动相A为含2.84 g/L硫酸钠+2.60 g/L溴化四丁基铵的水溶液,流动相B为甲醇(A∶B=40∶60,体积比),等度洗脱,二极管阵列检测器于波长220 nm和230 nm处检测,利用保留时间和光谱图定性,外标法定量。结果表明,5种物质在10 min内分离完全,在1μg/mL～200μg/mL范围内线性关系良好,相关系数均大于0.999 5,检出限(LOD)为0.016 mg/kg～0.039 mg/kg(信噪比S/N=3)。在20.0 mg/kg～120.0 mg/kg添加水平下,平均回收率为89.5%～101.6%,相对标准偏差RSD为0.98%～3.07%(n=4)。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

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.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

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.