热脱附气相色谱质谱法测定PVC人造革袋式法VOC中甲苯散发量的不确定度评定

轻工行业标准《人造革合成革试验方法挥发性有机化合物的测定》采用热脱附气相色谱质谱法,对人造革合成革袋式法挥发性有机化合物进行测定。本文依据该轻工行业标准规定的方法,按照JJF 1059.1-2012《测量不确定度评定与表示》中的规定,选用国产的PVC人造革样品,对其袋式法挥发性有机化合物中甲苯的不确定度进行评定,主要分析了检测过程中引入不确定度的三个因素,分别为气体采样泵引入的不确定度,标准物质引入的相对标准不确定度,标准工作曲线拟合引入的相对标准不确定度,得出当甲苯的测试结果为76.8μg/m3时,取扩展因子k=2(置信概率95%),扩展不确定度为11.0μg/m~3。     

聚氯乙烯人造革中挥发物含量测量不确定度的评定

以一个聚氯乙烯人造革样品为例,按照GB 21550-2008《聚氯乙烯人造革有害物质限量》测定聚氯乙烯人造革中其他挥发物有害物质含量,分析了测试过程中不确定度的来源,对各不确定度分量进行评定及合成,并计算得出了合成不确定度和扩展不确定度。     

土工布梯形法撕破强力测试不确定度评估

按照GB/T 13763-1992《土工布梯形法撕破强力试验方法》对土工布的撕破强力进行测试,并结合国家计量规范《测量不确定度的评定与表示》对实验结果进行测量不确定度评估,通过利用方差分析等数理统计的方法对引起不确定度的来源进行分析并量化,最终得出扩展不确定度。     

鞋面用聚氨酯人造革耐磨耗性测量不确定度评定

测量不确定度是一种对测量结果可信程度的表示方式,QB/T 2780-2006《鞋面用聚氨酯人造革》中规定了鞋面用聚氨酯人造革耐磨耗性的测定方法,按照QB/T 2780-2006标准测定鞋面用聚氨酯人造革的耐磨耗性,分析了测试过程中不确定度的来源,建立了耐磨耗性不确定度的试验模型,对操作过程的重复性、试片称量、耐磨试验仪本身、数值修约等不确定度分量进行评定及合成,并计算得出合成不确定度和扩展不确定度。结果表明,影响耐磨耗性的测量不确定度主要来自操作过程的重复性,这与鞋面用聚氨酯人造革涂层的不均匀性、试验环境的温度和湿度、人员操作习惯等因素有关。     

使用胶粘剂对针织人造服装革剥离强度的影响研究

本文通过对比15种不同种类的针织人造革服装,对比在粘胶和不粘胶情况下剥离强力的力值改变。结果表明,胶粘剂的使用可以很大程度地提高剥离强力的测试结果。按照FZ/T 73028—2017《针织人造革服装》4.2.7剥离强力的测定,不使用胶粘剂,直接测试时若能将涂层与基布剥开,剥离强力力值基本达不到标准合格品要求。     

鞋类钢勾心硬度和纵向刚度测试不确定度的评估

对GB28011-2011《鞋类钢勾心》中的硬度和纵向刚度两个强制性检测项目的测试不确定度进行了评估,讨论了硬度和纵向刚度的测量不确定度的产生原因及其评定方法,并对不确定度各个分量进行评定、合成,最后给出了合成不确定度及扩展不确定度。通过不确定度的分析提出了试验中的注意事项。     

机织物裤形试样撕破强力测量不确定度分析

试验结果的完整性依赖于不确定度的准确评估。依据GB/T 3917.2—2009《纺织品织物撕破性能第2部分：裤形试样（单缝）撕破强力的测定》对同一块机织物的撕破强力进行了50次（经纬向各25次）测试,并按照JJF 1059.1—2012《测量不确定度评定与表示》对影响测量结果的不确定度进行了分析,明确了随机效应产生的不确定度分量、仪器示值偏差引起的不确定度分量和数值修约产生的不确定度分量,得出了合成标准不确定度及扩展不确定度。结果表明：数值修约产生的不确定度为主要来源;机织物裤形试样经向撕破强力为（17±1）N,纬向撕破强力为（13±1）N,包含因子k=2。     

超高效液相色谱-串联质谱法测定牛奶中强力霉素残留的不确定度评估

目的采用超高效液相色谱-串联质谱法对牛奶中强力霉素残留的不确定度进行评估。方法测定牛奶中的强力霉素,建立该方法测定牛奶中强力霉素含量不确定度的数学模型,确定不确定度来源并对其评定。结果当牛奶中强力霉素含量为0.052μg/g时,其扩展不确定度为0.0056μg/g(k=2)。其中,测量重复性和标准曲线对不确定度的影响最大。结论通过采用超高效液相色谱-串联质谱法测定牛奶中强力霉素含量应严格控制实验条件,保证实验具有良好的重复性,另外还要保证标准曲线具有良好的线性。     

非织造布撕破强力测试的不确定度分析

按照FZ／T60006—1991《非织造布撕破强力的测定》的梯形法测定纺粘法PP非织造布的撕破强力,并结合JJF1059—1999《测量不确定度评定与表示》评定了重复测量、仪器示值误差、修约精度及横梁移动速度精度对撕破强力测量结果不确定度的影响,计算得出了各参数的标准不确定度、合成标准不确定度和扩展不确定度。     

原子荧光光谱法测定香菇中砷的不确定度评定

通过以原子荧光光谱法对香菇中的砷进行测定,分析和识别测定过程中各个不确定度分量,确立评定函数模型,计算合成标准不确定度和扩展不确定度,从而建立香菇中砷测定的不确定度评定方法。评定结果表明:样品制备对实验的测量不确定度影响最大,因此样品制备过程中应严谨操作,注意样品消解条件的控制。该评定模型可为采用此方法测定香菇中砷的质量控制提供参考。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press