功能性纺织品的功能评价方法与标准化现状(二)

3 纺织品抗紫外性能的评价方法与标准 到达地球表面的太阳光，其波长范围为280—30000nm，分别由紫外线（5％）、可见光（50％）和红外线（45％）组成。其中，紫外线由波长较短、强度较大的UV—B（280—315nm）和波长较长、能量较低的UV—A（315—400nm）及波长小于280nm的UV—C组成。紫外线是一种对人类既有利又有害的电磁波，它有助于人体内维生素D的合成和钙的吸收，同时还具有杀菌、消毒的功效，但过量的紫外线会使人体皮肤产生红斑、皮炎、色素沉积，甚至引起皮肤癌。研究表明，     

太阳镜镜片透射比特性的计算机计算

1、光的基础知识 光是一定波长的电磁波，光辐射测量所涉及到的波长范围：包括波长为380nm-780nm的可见光区域；波长大于780nm而小于1mm的红外光区域；波长380nm-1nm的紫外光区域。而紫外线辐射则大致分为三个区：380nm-315nm的UVA区；315nm-280nm的UVB区：以及280nm-10nm的UVC区。由于波长小于280mm的紫外线光辐射极易被空气强烈吸收，所以在太眼镜的要求指标中不予考虑。     

防紫外纺织品耐久性及耐洗涤性能研究

本文选择37批次明示或宣称具有防紫外线功能的纺织品,对不同贮存时间和不同洗涤次数的样品按GB/T 18830—2009《纺织品防紫外线性能的评定》测试。结果显示：随着时间的延长,防紫外性能减弱,贮存一年的防紫外纺织品九成以上保持90%以上的防紫外性能;贮存两年的防紫外纺织品四成能保持90%以上的防紫外性能,六七成存放两年的防紫外纺织品能保持80%以上的防紫外性能。随着洗涤次数的增加,防紫外性能减弱,洗涤2次后八九成的防紫外纺织品,洗涤3次后六七成的防紫外纺织品,洗涤5次后四五成的防紫外纺织品,洗涤10次后两三成的防紫外纺织品,洗涤15次后约两成的防紫外纺织品可保持90%以上的防紫外性能。建议防紫外纺织品在标识标签中体现具体的UPF值,以供消费者择优选购。     

防紫外线纺织品的现状及发展趋势

叙述了防紫外线屏蔽剂、防紫外线纺织品生产方法、纺织品防紫外线性能影响因素及防紫外线性能测试的研究现状,预测了防紫外线织物的三种发展趋势。     

防紫外线织物的护肤作用和测试

经过紫外线防护整理的纺织品可实现有效的紫外防护。文中从新的测试原理、防紫外线纺织品对皮肤的防护效果、防紫外线纺织品防护DNA基因受到损伤和按照紫外线标准801测定的纺织品紫外线防护指数等方面阐述了纺织出是否能对皮肤提供足够防紫外线辐射的作用和是否能进行有效测试等问题。新的生物试验方法在实际应用中初次模拟日光紫外线辐射和人体皮肤之间的相互作用影响,并定量分析由此产生的损伤。     

防紫外线棉织物的开发与研究

概述了防紫外线辐射纺织品的作用机理。以夏季服用面料纯绵针织物为防紫外整理对象,通过不同工艺参数的试验,选出最优工艺条件,并测试与分析防紫外线织物的性能。     

植物防紫外线整理剂性能研究

对8种常见天然植物进行紫外线吸收剂的提取,并对提取液进行了紫外吸收光谱特性分析,确定了防紫外线整理剂的最佳方案。对真丝织物先用金属离子络合,再用防紫外线整理剂浸渍整理,测试其防紫外线性能。实验结果表明,不同植物提取液对紫外线的吸收效果不同,可选择黄柏、蒲公英和绿茶3种植物来制备防紫外线复配液,经其处理的丝织物防紫外线能力明显增强,该复配液可作为一种天然的紫外线吸收剂应用在纺织品上。     

织物防紫外线性能测试仪的研制

为了测试和评价纺织品的防紫外线性能,详细介绍了基于 GB/T18830—2002《纺织品防紫外线性能的评定》研制的织物防紫外线性能测试系统的组成、基本功能,并对其功能的实现、考核及应用做了分析.该测试系统以紫外分光光度计为基础,通过专用的织物样品夹持架便于测试样品不同部位,通过 RS232通讯口将测试数据传送到计算机中,由专门研制的软件系统进行处理;测试系统给出织物的 UVA、UVB紫外线透过率、紫外线防护系数 UPF 值,以及不同波长下紫外线透过率曲线图;具有操作简单、测试速度快、精度高、仪器稳定性好的优点;但织物均匀性较差时,不同测试部位得到的测试结果可能会相差比较大,应通过增加测试部位和次数来改善测试结果     

防紫外线织物的最新研究进展

概括介绍了防紫外线织物的制备方法及其效果评价,着重讨论了纺织品防紫外辐射的性能和紫外线屏蔽剂的最新研究进展。     

防紫外线化纤纺织品技术的发展

利用化纤纺织品抗紫外是各国防紫外线研究与发展的重点,其相关材料和工艺技术标准化、产业化发展日益成熟.简要介绍了防紫外线化纤纺织品的发展现状、标准和分类,对目前各种防紫外线化纤纺织品所能达到的性能及发展现状做了详细比较,并展望了化纤类防紫外线纺织品技术的发展趋势.     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.