Ho@TiO2催化剂的制备及其可见光光催化降解性能

以钛酸四丁酯、氯化钬六水合物、无水乙醇为原料,采用简单的溶胶-凝胶法,成功制备出了Ho金属元素掺杂的Ho@TiO₂纳米光催化剂。采用XRD、FT-IR和PL等技术,对样品的晶体结构和性能进行表征,并优化了Ho@TiO₂纳米光催化剂配比,以玫瑰红B模拟废水进行探针反应,在可见光照射下评价其光催化性能。结果表明,与TiO₂纳米催化剂进行对比,Ho@TiO₂纳米光催化剂对玫瑰红B溶液(5 mg/L)表现出更高的可见光光催化降解性能,在可见光下照射180 min的脱色率达到95%。     

Yb-TiO2复合光催化剂的制备及光催化性能

基于TiO₂主体材料,通过镱掺杂改性制备了Yb-TiO₂纳米光催化剂,并用XRD、FT-IR和PL等技术对样品的晶体结构和性能进行表征,优化了Yb-TiO₂纳米光催化剂配比(0.8%),并以玫瑰红B模拟废水进行探针反应,分别在紫外光和可见光照下评价其光催化性能。与未掺杂TiO₂纳米光催化剂进行对比,Yb-TiO₂纳米光催化剂对玫瑰红B溶液表现出更高的光催化降解性能,在紫外光(90 min)和可见光(180 min)下的脱色率分别达到99%和90%。     

FePc/TiO2负载纳米纤维膜制备及光催化性能

使用静电纺丝技术制备聚丙烯腈(PAN)纳米纤维,通过对其化学改性引入偕胺肟基团,然后借助配位作用同时负载酞菁铁(FePc)和二氧化钛(TiO₂)制备了光催化剂,在对其形态结构和光吸收特性进行表征的基础上,考察其在有机染料氧化降解中的光催化性能。结果表明,FePc和TiO₂能够有效负载于改性PAN纳米纤维表面,并使其形貌发生明显变化。FePc能够作为光敏剂拓宽TiO₂催化剂的光谱响应范围,使其在可见光区显示出较强吸收,从而能够在可见光辐射下对染料的氧化降解反应显示出较高的光催化活性。此外,当改性PAN纳米纤维增重率为30.4%时,制备的光催化剂显示出最佳活性,而且其催化活性与可见光强度呈正相关性。     

改性TiO2的制备及其在壁纸中的应用研究

以纳米TiO_2 (P25)为改性对象,通过简单的一步水热法制备了具有可见光催化活性的N掺杂改性P25光催化剂 (N-P25),借助X射线衍射仪、紫外-可见光谱仪和扫描电子显微镜对N-P25的结构进行表征;再将其涂布于壁纸上,通过对壁纸物理性能和光催化降解甲醛性能的综合对比选择最佳涂布工艺。结果表明,N-P25仍为混晶结构,但对可见光的响应得到提升。在最佳涂布工艺条件下,N-P25涂布量1. 5g/m~2的壁纸在日光灯照射6 h后,对甲醛的降解率可达87%;且对不同初始浓度甲醛的光催化降解符合LH一级反应动力学规律。     

二硫化钼/聚丙烯腈复合纳米纤维膜的制备及其光催化性能

采用水热合成法制备了无机半导体光催化剂二硫化钼(MoS_2),利用静电纺丝技术,将MoS_2粉末添加到不同质量分数的聚丙烯腈(PAN)溶液中进行共混纺丝,制备MoS_2/PAN复合纳米纤维膜,并用于罗丹明B溶液的催化降解。借助扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X-射线衍射(XRD)等对纳米纤维膜的形貌和性能进行表征。结果表明:MoS_2/9%PAN复合纳米纤维膜中的纳米纤维形貌较好,直径较均匀,MoS_2在纳米纤维上的分布也较为均匀;使用其对30 mL的10 mg/L罗丹明B溶液进行光催化降解,光催化效果好,降解率达89.8%,重复使用3次后,降解率仅下降了2.3%,表现出良好的循环使用性。     

弱酸性染料的铁氮共掺杂纳米TiO_2光催化降解

以硝酸铁为铁源、尿素为氮源、钛酸四丁酯为钛源,采用溶胶-凝胶法制备铁氮共掺杂纳米TiO2光催化剂(Fe—N—TiO2)。利用X射线衍射仪(XRD)、红外光谱仪(FT-IR)和紫外-可见吸收光谱仪(UV-Vis),表征分析所制备的Fe—N—TiO2光催化剂的晶体结构和光谱性质;以弱酸性红RN染料为目标降解物,研究测试其可见光催化性能。结果表明,所制备的Fe—N—TiO2光催化剂为锐钛矿相,平均粒径为17.1 nm;其吸收边带红移至528 nm,禁带宽度为2.35 eV。在300 W金卤灯照射下,光催化反应240 min,0.12 g Fe—N—TiO2光催化剂对100mL质量浓度为5mg/L、染液初始pH值为5的弱酸性红RN染料的降解率达97.28%。     

Ag_3PO_4/TiO_2负载功能织物的制备及其光催化性能

采用原位沉积法制备Ag_3PO_4/TiO_2复合光催化剂,并经浸轧工艺整理1,2,3,4-丁烷四羧酸(BTCA)处理的棉织物,制备可见光光催化功能棉织物。采用X-射线衍射仪(XRD)、紫外-可见漫反射光谱(DRS)以及扫描电镜(SEM)表征复合光催化剂的晶型、光学性能以及整理织物的表面形貌,并研究了光催化功能织物催化降解模拟染料罗丹明B和甲醛的性能。结果表明,BTCA处理棉织物可以明显提高复合光催化剂在棉织物表面的负载量,所制得的可见光光催化功能棉织物对罗丹明B的降解率可达100%,对甲醛的降解率可达70%,具有良好的可见光光催化降解性能。     

BiPO4/g-C3N4异质结光催化剂的制备及其光催化性能

以BiPO₄和g-C₃N₄为前驱体，采用混合法制备了BiPO₄/g-C₃N₄复合光催化剂。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)、高分辨率透射电镜(HRTEM)、紫外可见漫反射光谱(UV-vis DRS)和荧光光谱(PL)等技术对BiPO₄/g-C₃N₄复合光催化剂的物相晶型、微观形貌以及光催化性质进行了表征。以甲基橙(MO)溶液为模拟染料溶液，对BiPO₄/g-C₃N₄复合光催化剂的光催化活性和循环使用稳定性进行评价，并对其光催化降解MO染料溶液机理进行了探究。结果表明：一维BiPO₄纳米棒锚定在二维g-C₃N₄纳米片表面形成异质结，拓宽了光谱范围，提高了对可见光的响应强度，抑制光电子-空穴的复合，提高了光催化活性。可见光照射3...     

掺杂纳米TiO2棉织物的自清洁性能

采用氧化沉淀法,锌与TiO2的质量比为0.3%,制备了锌离子掺杂纳米TiO2光催化剂。掺杂纳米TiO2可使5 mg/L亚甲基蓝溶液在紫外光下达到56.75%的降解率,可见光下达到42.93%的降解率。将Zn2+/TiO2质量比为0.4%的掺杂纳米TiO2整理到棉织物上,表现出较强的自清洁性能。在紫外光或是可见光照射16 h后,棉织物上的辣椒油污渍基本完全分解。     

无机盐对TiO2催化降解活性染料的影响

制备了可见光响应型纳米TiO2光催化剂,研究在无机盐存在下,TiO2对均三嗪型活性染料的光催化降解机制。结果表明,氯化钠对TiO2光催化降解活性染料既有促进作用又有抑制作用,其取决于氯化钠的浓度;硫酸钠对TiO2的光催化性能只有抑制作用,且随硫酸钠浓度的增大而增加;无机盐对X型活性染料活性艳蓝X-BR的光催化脱色没有影响,但适量的无机盐能促进K型活性艳蓝K-GR的降解。不同pH值条件下,无机盐对活性染料光催化脱色的影响不同,在酸性条件下无影响,中性和碱性条件下影响较明显,脱色率由大到小依次为:酸性>碱性>中性。     

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