羊毛/桑蚕丝混纺产品定量检测方法的探讨

采用常温硫酸法、40℃硫酸法、甲酸/氯化锌法、盐酸法4种不同的试验方法,将桑蚕丝从羊毛/桑蚕丝混纺产品中溶解去除,用修正后的质量计算羊毛、桑蚕丝各自的质量分数。对比分析了不同方法的试验数据,给出了在日常检测中更能保证检测结果准确性和稳定性的试验方法。     

桑蚕丝/羊毛纤维混纺织物定量化学分析方法的探讨

文章采用硫酸法和甲酸/氯化锌法,对五种不同配比的桑蚕丝/羊毛纤维混纺织物进行试验,探讨在定量化学分析中可以优先选择的试验方法。试验是利用桑蚕丝和羊毛在试剂中的溶解性差异,溶解去除混纺织物中的桑蚕丝,收集残留物,进行清洗和烘干后,对不溶残留物进行称重,用修正后的质量计算不溶组分羊毛占混纺织物干燥质量的净干质量分数,再由差值得出溶解组分桑蚕丝的净干质量分数。两种试验方法得到的试验结果表明,硫酸法和甲酸/氯化锌法的含量偏差均符合±5%的含量允差范围。在试验过程中,通过研究分析两种试验方法对不同配比混纺织物造成的结果差异,发现硫酸法测得的羊毛含量始终高于配比值。尤其是当羊毛含量高于30%后,差异更为明显。用甲酸/氯化锌法进行试验时,羊毛含量的偏差均小于1%,数据的稳定性和重现性好,结果更为准确。因此,桑蚕丝/羊毛纤维混纺织物在定量化学分析时,应优先使用甲酸/氯化锌法进行试验,这样结果的准确性能得到保证。     

羊毛／桑蚕丝混纺产品定量方法比较研究和优化

本文通过使用GB／T2910．18—2009和FZ／T 01048—1997两个标准中的方法对一系列羊毛／桑蚕丝混纺产品进行定量试验,比对两种方法得到的混纺产品中羊毛纤维的含量,观察残留物,并分析两种方法的优缺点,尤其是针对存在桑蚕丝溶解残留的深色产品优化了试验方法,得出了一种结果相对更准确、稳定性更好的定量方法,提高了深色羊毛／桑蚕丝产品定量的效率和复现性。     

羊毛与桑蚕丝混纺产品定量分析的探讨

目前羊毛、桑蚕丝的混纺产品定量化学分析方法主要采用GB/T2910.18—2009中的75%硫酸法和FZ/T01112—2012中的甲酸氯化锌法,但浓硫酸法和甲酸-氯化锌法配制及使用都有一定的危险性,对环境也有一定的影响。本文介绍了浓盐酸法,将浓盐酸法与GB/T 2910.18—2009中的75%硫酸法、FZ/T01112—2012中的甲酸-氯化锌法方法进行对比,测试羊毛与桑蚕丝不同混纺比例试验结果的稳定性和重现性。结果表明,采用浓盐酸法测试羊毛与桑蚕丝混纺产品具有一定的可行性,浓盐酸法溶解桑蚕丝时对羊毛的损伤较小,试验误差最小,结果重现性最好,且试验时间较短,易操作。     

羊毛/蚕丝保暖絮片的性能分析

通过对不同克重羊毛加入桑蚕丝进行混絮、绗缝处理,设计并制得共计3类13种不同规格的羊毛/桑蚕丝保暖絮片。通过测试试样的厚度、单位面积质量、热阻、蓬松度、透气率、压缩弹性率、水洗尺寸变化率等性能,分析比较了纯羊毛、羊毛/桑蚕丝絮片和绗缝羊毛/桑蚕丝絮片的保暖性及基本服用性能的差异。试验结果表明:羊毛/桑蚕丝保暖絮片的保暖性、絮片面密度稳定性均优于纯羊毛絮片,同时保持了羊毛絮片优良的压缩弹性;绗缝工艺处理后的羊毛/桑蚕丝絮片的耐水洗性能显著提升;但桑蚕丝的混入会降低絮片的透气性和蓬松度。     

基于热失重方法对羊毛/桑蚕丝混合物的定量分析方法研究

羊毛/桑蚕丝混合物的定量通常使用酸性试剂溶解桑蚕丝,但需要对羊毛进行质量修正。使用热重分析仪可以获得羊毛、桑蚕丝及其混合物在300℃的质量残留率,通过计算可得混合物中羊毛和桑蚕丝的百分含量。热失重方法定量羊毛/桑蚕丝混合物方便快捷,同时可以减少对环境的污染。     

羊毛/桑蚕丝/腈纶混纺产品定量分析方法的研究

为了解决GB/T 2910.2—2009溶解羊毛/桑蚕丝/腈纶混纺产品时存在因不能完全溶解纤维、剩余物难以收集而造成定量结果不准确的问题,本文采用甲酸/氯化锌在(70±2)℃下溶解桑蚕丝、腈纶和1mol/L次氯酸钠溶液溶解羊毛、桑蚕丝以定量分析羊毛/桑蚕丝/腈纶混纺产品。通过与标准方法做比较,结果表明,新方法在时效性上要优于传统方法,且拥有更高的精确度,此方法可用于羊毛/桑蚕丝/腈纶混纺产品的定量化学分析。     

蛋白质纤维/氨纶混纺产品纤维含量的测试与分析

为正确把握蛋白质纤维与氨纶混纺产品的服用性能与生产工艺,需要对该类产品的混纺比进行准确的测定。以天然蛋白质纤维中的羊毛和桑蚕丝纤维为例,采用二甲基甲酰胺法、次氯酸盐法及拆分法分别对5种不同的羊毛/氨纶混纺产品和桑蚕丝/氨纶混纺产品纤维含量进行测试与对比分析,试验结果完全符合FZT 01095—2002《纺织品氨纶产品纤维含量的试验方法》和GB/T 2910.4—2009《纺织品定量化学分析第四部分:某些蛋白质纤维与某些其他纤维的混合物》的要求。且在测试中从纤维溶解过程来看,采用次氯酸钠盐法测试蛋白质纤维与氨纶纤维的含量比用二甲基甲酰胺法更为合理。为蛋白质纤维与氨纶纤维混纺产品纤维含量测试与分析提供了很好的依据。     

甲酸/氯化锌法对深色桑蚕丝/羊毛混纺产品的定量化学分析研究

由于深色桑蚕丝/羊毛混纺产品的桑蚕丝在甲酸/氯化锌溶液(水浴温度40℃,溶解时间45min)中不能完全溶解,故提出先使用保险粉剥色,再进行定量化学分析的方法。经过试验得出,保险粉对羊毛纤维基本没有损伤,且定量分析结果与产品设计值一致,此方法是可行的。     

羊毛/桑蚕丝混纺织物定量分析方法的研究与探讨

文章采用75%硫酸溶液和35%盐酸溶液两种方法,定量地比较和分析了6组不同比例的桑蚕丝羊毛混纺织物含量的测试结果差异。     

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