高效液相色谱荧光法检测海产品中苯并(a)芘及其代谢产物

目的 建立检测海产品中苯并(a)芘(BaP)及其代谢产物3-羟基苯并芘(3-OHBaP)的高效液相色谱荧光法(HPLC-FD).方法 样品经65％乙腈提取,涡旋混匀,离心沉淀,分别以甲醇-水(pH 4.5)(85∶ 15)、(87∶ 13)为流动相进行色谱分离BaP、3-OHBaP,色谱柱为Century SIL C18-BDS(150 mm×4.6 mm,5μm),流速1.0 ml/min;荧光检测器检测BaP激发波长265 nm,发射波长450 nm,检测3-OHBaP激发波长365 nm,发射波长450 nm;进样量20μl.结果 BaP在0.1～10.0 ng/ml浓度范围内线性关系良好,相关系数r=0.999 4;3-OHBaP在1.07 ～100.7 ng/ml浓度范围内线性关系良好,相关系数r=0.992 1.BaP、3-OHBaP回收率分别在96.8％～ 112.0％、72.6％～ 83.3％之间;相对标准偏差分别为6.0％、5.2％(n=5);最低检测限分别为0.1和0.2μg/kg.结论 该法简便、快速、灵敏度高,可用于海产品中BaP及其代谢产物3-OHBaP的检测.     

超高效液相色谱-荧光检测法测定禽肉组织中乙氧酰胺苯甲酯残留量

建立超高效液相色谱-荧光检测法测定禽肉组织中乙氧酰胺苯甲酯（ethopabate,ETP）残留量的分析方法。样品用乙腈提取,采用C18色谱柱（2.1 mm×100 mm,1.8 μm）,乙腈-水（30∶70,V/V）为流动相,流速0.3 mL/min,柱温30 ℃,进样量5.0 μL,采用荧光检测器,在激发波长272 nm、发射波长394 nm条件下测定。结果表明：ETP在5～500 ng/mL质量浓度范围内呈良好的线性关系（R2=0.999 7）;检出限为2 μg/kg,定量限为5 μg/kg;平均回收率为83.0%～91.5%,相对标准偏差为1.6%～2.9%。本方法适用于检测禽肉组织中ETP残留量。     

HPLC测定牛奶和虾仁中氯霉素残留

建立了一种检测虾仁和牛奶中氯霉素残留的高效液相色谱(紫外检测,即LC/UV)方法和液相色谱-电喷雾电离质谱联用(LC/ESI MS)检测方法.色谱分离选用SymmetryC18柱,以乙腈-水为流动相.紫外检测波长为278nm,质谱采用选择性离子检测(M/Z321.0,[M H]-).样品制备省去传统的多次液 液萃取过程,采用有机溶剂直接提取,转溶后,用固相萃取方法净化样品.虾仁和牛奶样品的平均回收率分别为93.7%和96.0%;检测限:LC/UV为2.5μg/kg和8.3μg/kg;LC/ESI MS为1.3μg/kg和4.5μg/kg.方法准确灵敏,样品预处理较简便快速.     

HPLC法测定乳饮料中纽甜含量的研究

建立快速、准确测定乳饮料中纽甜含量的高效液相色谱检测方法。样品以20%乙腈水溶液为提取液,硫酸锌和亚铁氰化钾为沉淀剂进行前处理,采用ZORBAX SB-C18(250 mm×4.6 mm,5μm)色谱柱,200 nm检测波长,磷酸氢二铵(0.020 mol/L,pH 3.5~4):乙腈=(70∶30)为流动相进行等度洗脱分离。纽甜在0.2μg/m L~50.0μg/m L范围内线性良好,在0.8 mg/kg~5.0 mg/kg加标范围内,回收率为90.1%~96.1%,RSD值为1.7%~2.1%,最低定量限为0.30 mg/kg。     

高效液相色谱法测定调味品中"对位红"含量

建立了调味品中“对住红”含量的高效液相色谱测定方法。调味品样品用乙腈超声提取，以SB-C18柱作为分离柱，用乙酸溶液／乙腈（30：70）为流动相，流速0．7mL／min，波长482nm，进样20μL进行液相色谱分析。在10～100μg／kg范围内，方法回收率在83．1％～98．6％之间。最低检测浓度可达5μg／kg，具有良好的准确性和精密度。     

固相萃取-高效液相色谱-荧光检测法测定水产品中4种丁香酚类化合物

目的建立固相萃取-高效液相色谱荧光法测定水产品中4种丁香酚类化合物(丁香酚、异丁香酚、甲基丁香酚、甲基异丁香酚)残留的方法。方法样品用乙腈提取,中性氧化铝和C18固相萃取柱净化,Inertsil ODS-SP C18柱(4.6 mm×250 mm,5μm)分离,以甲醇-乙腈(1∶1,V/V)和1%冰乙酸水溶液为流动相,荧光检测激发波长为280 nm,发射波长为320 nm,外标法定量。结果 4种丁香酚类化合物在各自范围内线性关系良好,相关系数均0.999,方法检出限为3.0~6.0μg/kg,方法定量限为10.0~20.0μg/kg,平均加标回收率为74.7%~103.0%,相对标准偏差(RSD)为2.6%~8.1%。结论本方法操作简便、灵敏度高、实用性强,适用于水产品中丁香酚、异丁香酚、甲基丁香酚、甲基异丁香酚的残留分析检测。     

高效液相色谱法测定大米和小麦粉中的苯并(α)芘

以大米和小麦粉为样品,环己烷提取浓缩后用Phenomenex Luna C_(18)色谱柱分离,流动相为乙腈∶水=88∶12,流速为0.8 mL/min,荧光检测器(激发波长365 nm,发射波长410 nm)检测其中苯并(α)芘的含量。结果表明:苯并(α)芘在0.379~48.5μg/L范围内线性关系良好,相关系数r=0.999 9,在0.30~5.00μg/kg加标水平时,回收率为86.08%~98.17%,相对标准偏差为1.87%~4.22%(n=6);方法的检出限和定量限分别为0.1μg/kg和0.3μg/kg。该方法测定大米和小麦粉中的苯并(α)芘简单、快速、准确可靠。     

凝胶渗透色谱-气相串联质谱同时测定海产品中34种多氯联苯和76种农药

建立海产品中34种多氯联苯和76种农药气相色谱-串联质谱分析方法。用乙腈为萃取溶剂,均质法均质提取样品,盐析法除水,凝胶渗透色谱净化,收集26~50 min流出液,在线浓缩。用气相色谱柱(DB-1701)分离后,在多离子反应监测模式(MRM)下进行质谱检测。在1.0~500μg/kg范围内线性关系良好(R2﹥0.99),方法检出限(LOD)0.05~108.43μg/kg。空白样品添加回收率51.6%~120.5%,相对标准偏差范围0.84%~24.5%,回收率60%~110%,目标化合物为106种。该方法通用性强,选择性好,灵敏度、准确度和精密度均符合多残留检测的技术要求,适用于动物源性海产品中多残留的日常检测。     

测定维生素B1含量的HPLC法

以C18为分离柱，以100mmol/L磷酸钠缓冲溶液（pH2.1）/0.8mol/L辛基磺酸和乙腈=9：1（v/v）混合液为流动相，检测波长为270nm的液相色谱检测VB1含量，在0.005μg～2.5μg范围内进样与主峰面积线性关系良好（r=0.9997），最小检测量0.0050μg，检出限0.0002μg。     

高效液相色谱—二极管阵列检测法测定原料乳中的舒巴坦

建立了利用高效液相色谱-二极管阵列法(high-performance liquid chromatography-photodiode array,HPLC-PDA)测定原料乳中舒巴坦含量的方法。采用C18色谱柱,以5.44g/L磷酸二氢钾溶液(pH5.0)-乙腈(95∶5)为流动相,流速为lmL/min,检测波长220nm,柱温30℃。样品经乙腈提取、乙酸锌沉淀蛋白,HPLC-PDA检测。舒巴坦浓度在10～200μg/mL范围内,线性良好(R2=0.9998),添加回收率为98.82%～101.42%,检出限为0.25mg/kg,定量限为0.75mg/kg。该方法操作简单,结果准确、可靠,适用于原料乳中舒巴坦的快速检测。     

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.     

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.     

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.     

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.