分子印迹固相萃取-分光光度法检测环境水样中的孔雀石绿

目的建立分子印迹固相萃取-分光光度法检测水样中孔雀石绿的方法。方法以孔雀石绿(MG)为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,以本体聚合方法制备的分子印迹聚合物为填料自制固相萃取柱。对固相萃取的上样溶剂、干燥方法、淋洗溶剂等条件进行了优化。采用优化的条件对自来水和河水加标水样中的孔雀石绿进行萃取,再用分光光光度计检测。结果自来水和河水水样加标浓度在8～128μg/L范围内得到的回收率分别为86.3%～92.1%和83.5%～90.3%。结论本方法操作简单、灵敏度高,适用于环境水样中孔雀石绿的痕量检测。     

基于溶胶-凝胶技术的乐果分子印迹固相微萃取涂层的评价及应用

目的对溶胶-凝胶法制备的乐果分子印迹固相微萃取头进行评价,并建立分子印迹固相微萃取与气相色谱联用(molecularly imprinted polymer-solid phase microextraction/gas chromatography,MIP-SPME/GC)检测环境水中乐果残留量的方法。方法以非印迹(nonimprinted polymer,NIP)SPME萃取头为参照,考查乐果分子印迹(MIP)萃取头的使用性能;优化SPME萃取条件后,对MIP-SPME/GC方法的分析性能进行评价,最后检测实际样品。结果该MIP萃取头的热稳定性和化学稳定性高,在水相中萃取选择性好。在优化条件下,方法在蒸馏水中线性范围为12.5~2500μg/L,线性相关系数为0.9997,检出限为97.0 ng/L,5次重复实验所得RSD为6.45%。应用本方法测定湖水和自来水中乐果含量,均未有乐果检出。自来水中方法的加标回收率在92.0%~114.2%之间,湖水中加标回收率为88.9%~102.1%。结论溶胶-凝胶分子印迹SPME萃取头具有很高的操作稳定性,能够用于水相识别。本方法简便、精密度高、准确度好,在富水样品的乐果检测中具有明显优势。     

分子印迹固相萃取—高效液相色谱法检测鱼肉中的孔雀石绿和结晶紫

将分子印迹固相萃取和高效液相色谱法联用,建立一种检测鱼肉中孔雀石绿和结晶紫及其代谢产物残留的新方法。以孔雀石绿为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,本体聚合法合成分子印迹聚合物。并制成分子印迹固相萃取柱,优化分子印迹固相萃取的实验条件。鱼肉样品经过超声提取后,采用分子印迹固相萃取富集净化,用高...     

分子印迹固相萃取-高效液相色谱法测定 酱油中酪胺含量

目的 建立分子印迹固相萃取-高效液相色谱法检测酱油中酪胺含量的方法。 方法 以酪胺为模板分子、对乙烯基苯甲酸(P-VBA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,以本体聚合法制备的分子印迹聚合物为填料自制固相萃取柱。对上样溶剂、流速、淋洗及洗脱溶剂等条件进行优化,采用优化的条件萃取酱油中的酪胺,高效液相色谱测定。 结果 固相萃取优化条件为：上样溶剂为5%乙醇水溶液,1 mL 10%甲醇为淋洗液,3mL 40%乙腈为洗脱液,流速均控制在0.5 mL/min。在加标浓度为10μg/mL的3种酱油所得到的回收率在93.91%~101.39%之间。 结论 本方法能快速分离酱油中的酪胺,提高了样品前处理效率,且该方法灵敏度高,适用于食品中酪胺的痕量分析。     

分子印迹固相萃取-高效液相色谱法测定酱油中酪胺含量

目的建立分子印迹固相萃取与高效液相色谱联用快速测定酱油中酪胺含量的方法。方法采用本体聚合法以酪胺为模板分子,对乙烯基苯甲酸(P-VBA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,制备分子印迹聚合物为填料自制固相萃取柱。对上样溶剂、流速、淋洗及洗脱溶剂等条件进行优化,采用优化的条件萃取酱油中的酪胺,高效液相色谱测定。结果固相萃取优化条件为:上样溶剂为5%乙醇水溶液,10%甲醇为淋洗液,40%乙腈为洗脱液,流速均控制在0.5 mL/min。在加标浓度为5μg/mL和10μg/mL的3种酱油所得到的平均回收率在86.95%~106.06%之间。结论本方法能快速分离酱油中酪胺,样品前处理效率高,方法灵敏度高,适用于食品中酪胺的痕量分析。     

白藜芦醇分子印迹聚合物的应用及性能研究

采用分子印迹技术以白黎芦醇为模板分子,选择丙烯酰胺作为白藜芦醇印迹聚合物的功能单体,氯仿和四氢呋喃的混合溶液作为印迹聚合物合成溶剂,制备了白黎芦醇分子印迹聚合物,考察了分子印迹聚合物的吸附性能、选择性能以及固相萃取性能。优化分子印迹固相萃取的萃取条件,选择30%(体积分数)的乙醇-水溶液5 m L作为上样溶液,选择40%(体积分数)的乙醇-水溶液作为淋洗液、80%(体积分数)的乙醇-水溶液作为洗脱液。     

分子印迹固相萃取-高效液相色谱联用检测饲料中喹乙醇的研究

研究了以本体聚合法制备的喹乙醇分子印迹聚合物作为固相萃取填充材料,建立了分子印迹固相萃取与高效液相色谱联用技术检测饲料中残留痕量喹乙醇的方法。通过优化分子印迹固相萃取条件,确定用0.5ml甲醇-水(90∶10,V/V)洗脱液,在上样流速为1.2ml/min,样品在pH7~8条件下,对喹乙醇有较好富集效果。为了评价分子印迹固相萃取材料对模板分子喹乙醇的选择富集能力,分别以分子印迹聚合物和C18为固相萃取填充柱比较富集效果。在上样流速为1.2ml/min条件下,预富集42min,分子印迹固相萃取材料富集倍数达78,最低检测限(S/N=3)为88.0ng/L,连续在线富集5次的精密度(相对标准偏差)为4.6%。对添加有喹乙醇浓度为0.002 5和0.010 0mg/g的饲料进行检测,其添加回收率为89.5%和93.4%。     

分子印迹固相萃取-HPLC法检测食品中4种喹诺酮类抗生素

目的:建立检测鸡肉鸡蛋中4种喹诺酮类抗生素的分子印迹固相萃取-高效液相色谱(紫外检测器)的分析方法。方法:采用乳液聚合法制备诺氟沙星印迹聚合物(MIPs),采用扫描电镜和红外光谱对印迹聚合物进行表征。采用印迹聚合物为固相萃取剂,优化了影响萃取效率的参数包括淋洗剂的种类及用量、洗脱剂的种类及用量。结果:在优化的实验条件下,4种喹诺酮类抗生素在1.5～100μg/mL浓度范围内呈良好线性关系(r 0.992),方法的检出限(S/N=3)为0.04～0.4μg/mL,鸡肉鸡蛋样品中喹诺酮类抗生素的加标回收率为82.0%～96.0%,相对标准偏差(RSD)范围在3.9%～6.5%。结论:该方法快速、灵敏、可靠,能够满足食品中喹诺酮类抗生素多残留检测要求。     

基于分子印迹整体柱的在线固相萃取-液相色谱联用测定奶粉中四环素类兽药残留

目的建立高交联结构的分子印迹整体柱(molecularly imprinted polymer monolithic column,MIP-MC)制备方法,利用在线固相萃取与液相色谱联用技术检测奶粉样品中四环素类兽药残留。方法在不锈钢色谱柱中,以土霉素为模板,甲基丙烯酸和甲基丙烯酸羟乙酯为功能单体,乙二醇二甲基丙烯酸酯和双季戊四醇六丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,在丙酮-甲醇-十二醇混合溶剂中,制备了分子印迹整体柱。将整体柱与液相色谱联用,在线固相萃取奶粉中的四环素类兽药残留。结果在最佳在线固相萃取条件下,获得了较高的富集因子(19.3)和净化效果。四环素类在0.05、0.25和0.5 mg/kg 3个加标水平下,回收率为84.2%~103.4%,相对标准偏差为1.37%~4.87%,方法检出限(S/N=3)和定量限(S/N=10)分别为8.48~11.74?g/kg和28.24~39.09?g/kg。结论该在线固相萃取方法简单快速、灵敏性高、选择性好,适用于奶粉中四环素类抗生素残留的测定。     

分子印迹固相萃取-高效液相色谱法检测蜂王浆及其制品中的蜂王酸

目的:建立分子印迹固相萃取与高效液相色谱联用方法,检测蜂王浆及其制品中蜂王酸的含量。方法:采用分子印迹本体聚合法,经一系列优化,得到对蜂王酸具有特异识别能力和高吸附容量的分子印迹聚合物。将其作为固相萃取柱的填充材料,对蜂王浆样品中的蜂王酸进行分离和纯化,采用高效液相色谱检测。结果:被测样品用分子印迹固相萃取柱处理后的加标回收率为92.02%~103.28%,检出限(S/N=3)为0.94μg/L,线性范围10~1 000μg/L(R20.99),相对标准偏差(RSD)小于8.91%。结论:所建方法具有准确性和实用性,可用于蜂王浆及其制品中蜂王酸的分离纯化和检测。     

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.     

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.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the