高效液相色谱法测定原粮中玉米赤霉烯酮的改进研究

目的对原粮中玉米赤霉烯酮免疫亲和层析净化高效液相色谱测定方法进行改进和研究。方法样品粉碎后经体积分数为84%的乙腈溶液超声提取,采用免疫亲和柱净化,C18色谱柱进行分离,以乙腈-水-甲醇(46:46:8)为流动相,最后用高效液相色谱荧光检测器对玉米赤霉烯酮进行测定,激发波长为274 nm,发射波长为440 nm。结果在优化实验条件下,测得玉米赤霉烯酮的线性相关系数为0.9998,相对标准偏差为5.24%~7.96%,检出限为5μg/kg,加标回收率为92.6%~108.0%。结论改进后的方法适用于常用市售免疫亲和柱净化原粮中玉米赤霉烯酮。     

免疫亲和柱-高效液相色谱法测定谷物及其制品中玉米赤霉烯酮的含量

目的建立免疫亲和柱-高效液相色谱法分析检测谷物及其制品中玉米赤霉烯酮的方法。方法样品经乙腈-去离子水(84:16,V:V)提取,玉米赤霉烯酮免疫亲和柱富集净化,甲醇洗脱后,经C18反相色谱柱分离,以乙腈-水-甲醇(46:46:8, V:V:V)为流动相,使用高效液相色谱-荧光检测器检测,外标法定量。结果玉米赤霉烯酮在1～100μg/L线性范围内线性关系良好,相关系数0.9999,检出限0.8μg/kg,仪器重复测定的相对标准偏差0.19%,样品平行性测定相对标准偏差在0.10%～1.89%。检测成都市内综合农贸市场和超市内谷物及其制品中玉米赤霉烯酮的含量为1.34～43.1μg/kg,检出率为52.2%。结论该方法具有灵敏度高、重现性好、准确度高等特点,可应用于实际市场中谷物及其制品的痕量调查。     

免疫亲和柱-高效液相色谱法测定牛奶中氯霉素和玉米赤霉醇及其类似物

建立免疫亲和柱同时净化-高效液相色谱法测定牛奶中氯霉素和玉米赤霉醇及其类似物（α-玉米赤霉醇、β-玉米赤霉醇、α-玉米赤霉烯醇、β-玉米赤霉烯醇、玉米赤霉酮和玉米赤霉烯酮）残留量的方法。样品经免疫亲和柱净化与富集后,用高效液相色谱-紫外检测器检测。采用Cloversil-C18反相柱分离,流动相为乙腈-甲醇-水溶液,检测波长为265 nm。结果表明,牛奶中添加氯霉素和玉米赤霉醇及其类似物的回收率在74%～101%,且相对标准偏差均小于7%。氯霉素的检出限为0.02 μg/L,玉米赤霉醇及其类似物的检出限分别为α-玉米赤霉醇0.03 μg/L、β-玉米赤霉醇0.03 μg/L、α-玉米赤霉烯醇0.03 μg/L、β-玉米赤霉烯醇0.03 μg/L、玉米赤霉酮0.04 μg/L和玉米赤霉烯酮0.05 μg/L。该方法灵敏度高、重复性好,提高了检测速率,可满足牛奶样品中痕量氯霉素和玉米赤霉醇及其类似物残留的测定。     

单克隆免疫亲和柱-高效液相色谱法测定玉米中的玉米赤霉烯酮

研究了单克隆免疫亲和柱-高效液相色谱法测定玉米中玉米赤霉烯酮的方法。样品通过乙腈-水(体积比9：1)提取，提取液用免疫亲和柱净化，Waters C18色谱柱分离，荧光检测器检测，外标法定量。对添加不同含量的玉米赤霉烯酮进行6次重复实验，平均回收率为87．8％～90．9％，变异系数(CV)为8．6％～11．3％，检测低限为001mg／kg。     

免疫亲和净化-超高效液相色谱-串联质谱法测定食品中玉米赤霉烯酮类真菌毒素

建立食品中6种玉米赤霉烯酮类(α-玉米赤霉醇、β-玉米赤霉醇、α-玉米赤霉烯醇、β-玉米赤霉烯醇、玉米赤霉酮、玉米赤霉烯酮)真菌毒素的免疫亲和净化-超高效液相色谱-串联质谱检测的实验方法。样品经80%乙腈溶液提取,通过免疫亲和柱净化富集,用2 mL乙腈洗脱,氮吹至近干,0.5 mL 50%乙腈溶液复溶,采用超高效液相色谱-串联质谱进行测定。在ACQUITY UPLC HSS T3反相柱上分离,梯度洗脱,流动相为乙腈和水,质谱采集模式为电喷雾负离子多反应监测模式。6种目标物的线性范围为0.1~100μg/L,相关系数(R~2)均大于0.992,检出限为0.05μg/kg,定量限为0.2μg/kg,3个不同水平的加标平均回收率为73.0%~119.1%,相对标准偏差不大于10%。该方法具有操作简单、重复性好、灵敏度高、杂质干扰小等特点,可以用于食品中玉米赤霉烯酮类真菌毒素的检测。     

免疫亲和柱净化-HPLC法同时测定玉米制品中的赭曲霉毒素A和玉米赤霉烯酮

建立了同时测定玉米制品中赭曲霉毒素A和玉米赤霉烯酮的免疫亲和柱净化高效液相色谱方法。试样经乙腈-水溶液(体积比80?20)提取,复合免疫亲和柱富集和净化后,采用Syncronis C18色谱柱(250 mm×4.6 mm,5μm)固定相,以0.5%冰乙酸-乙腈-甲醇(体积比10?45?45)为流动相,等度洗脱,荧光检测器检测(Ex:333 nm,Em:470 nm)。结果表明:赭曲霉毒素A和玉米赤霉烯酮检出限分别为5.65×10-2μg/kg和4.53×10-1-μg/kg;标准曲线的线性范围分别为1~50 ng/mL(r=0.9999)和10~500 ng/mL(r=0.9999);3个不同水平的加标平均回收率为95.81%~98.31%,RSD值为1.24%~1.65%。20批试样中赭曲霉毒素A和玉米赤霉烯酮测定值分别为0.59~0.69μg/kg和3.84~5.22μg/kg,均无过量残留。该方法具有操作简便、灵敏度高、重现性佳等优点,适用于同时检测玉米制品中赭曲霉毒素A和玉米赤霉烯酮。     

高效液相色谱法对玉米中玉米赤霉烯酮的测定

研究了高效液相色谱法测定玉米中玉米赤霉烯酮的方法.样品借鉴了GB/T 19540-2004中提取玉米赤霉烯酮的方法,通过Oasis HLB净化柱对提取液净化,以agilent extent C18色谱柱为分离柱,乙腈-水(V水:V乙腈=55:45)为流动相进行荧光检测(λex=235 nm,λem=460 nm).玉米赤霉烯酮的质量浓度在12～2 400μ/kg范围内呈良好线性,相关系数为0.9994,对添加高、中、低3个浓度玉米赤霉烯酮的玉米样品进行加标回收试验,平均回收率分别为96.736%、93.839%、86.240%,变异系数在1%～10%之间,最低检测限为10μ/kg.此方法对玉米中玉米赤霉烯酮的检测是可行的,且可给谷物中玉米赤霉烯酮检测方法优化提供参考.     

免疫亲和柱净化—液相色谱法测定玉米油中的玉米赤霉烯酮含量

目的 建立免疫亲和柱净化—液相色谱法测定玉米油中玉米赤霉烯酮含量的分析方法。方法 样品采用乙腈-水(9:1, V:V)提取, 免疫亲和柱净化, 经Inertsil ODS3-C18柱 (250 mm×4.6 mm, 5 μm)分离, 以乙腈-水-甲醇(46:46:8, V:V:V)为流动相进行等度洗脱, 流速1.5 mL/min, 柱温30 ℃, 经荧光检测器检测, 外标法定量。结果 玉米赤霉烯酮在25~2500 μg/kg范围内具有良好线性, 相关系数为0.99998, 检出限5 μg/kg, 加标回收率为87.5%~107.5%, 相对标准偏差为3.2%~5.8%。对调和油中米赤霉烯酮质控考核样品Mycotoxin-PT-2018-042的检测结果满意。结论 该方法前处理操作简便, 损失少, 减少了试剂用量, 灵敏度高, 准确度高, 适用于玉米油中玉米赤霉烯酮的检测。     

免疫亲和柱净化-HPLC法测定小麦粉中的黄曲霉毒素B_1、玉米赤霉烯酮和脱氧雪腐镰刀菌烯醇的含量

建立了免疫亲和柱净化-高效液相色谱法测定小麦粉中黄曲霉毒素B1(AFB1)、玉米赤霉烯酮(ZEN)、脱氧雪腐镰刀菌烯醇(DON)的方法。小麦粉样品经乙腈-水振荡提取,三合一免疫亲和柱净化后,采用双通道荧光检测器串联光化学衍生器同时测定黄曲霉毒素B1和玉米赤霉烯酮,二极管阵列检测器测定脱氧雪腐镰刀菌烯醇。样品中各真菌毒素平均加标回收率为74.8%~105.2%,相对标准偏差为1.96%~6.26%。此方法可用于实验室开展小麦中3种真菌毒素含量的检测。     

免疫亲和柱——高效液相色谱法检测乳制品中玉米赤霉醇及其类似物

采用高效液相色谱法检测牛奶和奶粉中的6种玉米赤霉醇及其类似物,该方法准确、可靠、灵敏度高.样品用乙腈提取,经免疫亲和柱净化后,用高效液相色谱-紫外检测器检测.结果表明,牛奶和奶粉中添加6种玉米赤霉醇及其类似物回收率均为80％～110％,变异系数均小于12％.     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.