香兰素的铜掺杂碳量子点的荧光法检测

目的:建立一种基于铜掺杂碳量子点(Cu-CDs)的荧光检测方法用于食品中香兰素含量的分析.方法:以抗坏血酸作为碳源,乙酸铜作为金属掺杂剂,通过一步水浴合成法制备性能稳定的Cu-CDs,通过X-射线能谱、红外、紫外、荧光等技术对制备的Cu-CDs进行形貌、元素及光学性能的表征,并研究该碳点与香兰素的猝灭作用.结果:Cu-...     

荧光碳量子点在食品安全快速检测中的应用

碳量子点作为新兴的荧光碳纳米材料,因优良的荧光特性和生物相容性、且制备简单、廉价无毒的特点,受到了人们的广泛关注。本文介绍了碳量子点的合成方法、荧光检测机制,并综述了其在食品安全快速检测领域中的应用现状,以促进碳量子点的利用与发展,为进一步保护食品安全提供新思路。     

基于碳量子点荧光法测定药品中链霉素的含量

以L-半胱氨酸和葡萄糖作为碳源,采用水热法制备具有优良荧光效果的碳量子点,通过紫外吸收光谱以及荧光光谱等手段对其进行表征.以碳量子点为荧光探针,研究链霉素及溶液配制条件对荧光效果的影响.结果表明,溶液pH值为7.4时,激发波长为440 nm以及在5 mL容量瓶中加入1 mL的碳量子点进行定容,15 min后检测较合适....     

基于CdTe/CdS量子点荧光淬灭方法检测自来水和果汁中汞离子

本文基于巯基乙酸修饰的核壳型CdTe/CdS量子点建立了Hg2+的检测方法。对检测条件进行优化并利用荧光光谱仪和紫外-可见吸收光谱仪对量子点荧光强度进行表征。结果表明:在Tris-HCl缓冲溶液浓度为0.05 mol/L,pH8.0,室温反应15 min的条件下,不同浓度Hg2+(10-6~10-4 mol/L)对量子点具有较好的荧光猝灭效果,且随着Hg2+溶液浓度增加,其对量子点的荧光猝灭效果逐渐增强。该方法对Hg2+的理论检出限为2.667 nmol/L,低于自来水检测标准;对果汁样品中Hg2+的检测灵敏度为2.0×10-5 mol/L。因此,本研究为果汁体系中重金属的检测提供了一种新的思路和方法。     

荧光试纸技术可视化定量检测食品中的乙二胺四乙酸

目的 建立荧光试纸技术对食品中乙二胺四乙酸(editic acid, EDTA)进行可视化定量检测的方法。方法 以豌豆荚为原料，采用水热法合成蓝色荧光碳量子点（carbon quantum dots, CQDs），利用透射电镜（transmission electron microscope, TEM）、X射线衍射仪（X-ray diffractomer, XRD）、X射线光电子能谱仪（X-ray photoelectron spectroscopy, XPS）和傅里叶变换红外光谱仪（fourier transform infrared spectrometer, FTIR）对制备的CQDs的形貌及表面结构进行表征；向豌豆荚碳量子点溶液中加入铜离子（Cu2+），使蓝色荧光淬灭，将CQDs-Cu2+溶液吸附于滤纸上，制得EDTA荧光检测试纸。结果 EDTA能使CQDs-Cu2+体系淬灭的荧光恢复，在20~120 μmol/L范围内与CQDs-Cu2+荧光恢复强度呈现较好的线性关系，检出限为6.29 μmol/L，回收率为98.73%~99.40%。结论 该试纸可用于定量检测食品中EDTA的含量，为EDTA的检测提供更加简便、直观的方法。     

基于量子点的食源性致病菌快速检测方法研究进展

建立快速、灵敏、高效的检测方法有利于预防和控制食源性致病菌污染,对食品安全具有重要意义。量子点是新颖的荧光纳米晶体,具有独特的光学特性,如量子产率高、光稳定性好、斯托克斯位移大、激发光谱宽、发射光谱窄等,这些优点使其成为理想的生物探针。基于量子点的食源性致病菌快速检测方法包括:量子点免疫标记、免疫磁珠分离-量子点多重荧光免疫分析、适配体-磁珠和量子点夹心分析、基于荧光量子点的"三明治"模式抗体阵列、量子点免疫层析试纸条、量子点生物传感、量子点标记流式细胞术等。随着量子点合成工艺的不断改进以及量子点与免疫分析、适配体分析、生物传感等检测方法的结合,将会为人们提供更多快速、灵敏、高效的检测方法,在食源性致病菌检测领域将会有更广阔的应用前景。     

量子点在食品安全快速检测中的应用研究进展

作为一种新型的荧光纳米材料,量子点的应用范围已从材料学、生物医学领域扩大到食品领域,促进了食品安全快速检测技术的发展。本文阐述了量子点特有的光学性质,如宽的激发光谱、窄的发射光谱、可精确调谐的发射波长、良好的光稳定性等,并综述了量子点作为一种良好的荧光标记物,在致病菌、生物毒素、农兽药残留、非法添加剂和重金属等食品安全快速检测领域的应用进展情况。传统的检测方法存在检测时间长、灵敏度不高、样品前处理繁琐及对样品基质的抗干扰能力不强等缺点,难以满足实际检测的需求。而基于量子点的荧光检测方法弥补了这些缺点,必将越来越多地被应用于现代食品分析检测领域。     

丝素/角蛋白复合纳米纤维对Sb~(3+)的检测

采用静电纺丝法将碳量子点引入丝素蛋白/角蛋白复合纳米纤维中,制备一种具有荧光性能的可检测锑重金属离子的复合材料。结果表明,Sb~(3+)离子质量浓度不同,对纤维膜的荧光淬灭效果不同;荧光发射随着Sb~(3+)离子质量浓度的增加而逐渐减弱,在质量浓度为0.4 mg/L时基本可以完全淬灭,说明其具有检测锑重金属离子的能力。     

CdTe量子点作为荧光探针检测皮蛋中微量铜

基于CdTe量子点作为荧光探针建立了一种定量检测皮蛋中微量铜（Cu2＋）的荧光分析法。采用巯基乙酸和1-硫丙三醇作为稳定剂,水相中快速制得荧光性好、稳定性好的水溶性CdTe量子点,并运用紫外-可见分光光度和荧光光谱法研究CdTe量子点的发光特性。实验探究了Cu2＋对CdTe量子点荧光猝灭的机理,并根据Cu2＋浓度和荧光强度下降量之间的关系,在Cu2＋浓度范围为10～200 nmol/L时建立定量检测微量Cu2＋的线性方程,相关系数高达0.997,检出限低至0.96 nmol/L。本实验方法已经初步应用于皮蛋样品中Cu2＋的检测,结果显示相对标准偏差在1.47%～3.01%之间,回收率为104%～108%,说明了此方法的准确性、可靠性和适用性。     

CdTe量子点免疫层析试纸条检测克伦特罗

以巯基乙酸作为稳定剂,利用水热反应制备了水溶性的高荧光CdTe量子点,量子产率为54.961%。研究了该量子点在1-（3-二甲氨基丙基）-3-乙基碳二亚胺盐酸盐和N-羟基丁二酰亚胺的作用下与抗克伦特罗抗体的共价连接。结果表明：该量子点与克伦特罗抗体连接后体系的荧光强度和吸光度均增强,且峰位均未发生明显移动,F/P值为4.20。将该偶联反应物CdTe-Anti CLE pAb作为荧光标记物,组装出一种用于检测克伦特罗的荧光免疫试纸条,最低检测限达0.5 μg/L,与酶联免疫吸附法进行对比,该试纸条能够实现对克伦特罗的快速检测。     

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.     

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.     

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.     

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.     

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.     

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