全国化工标准物质委员会标准物质研究开发中心

<正>差示扫描量热仪温度检定/校准用系列标准物质[GBW(E)130174-130177]该系列国家标准物质由正辛烷、正十八烷、硫酸银、石英砂组成。采用高精度凝固点测量装置和相变温度测量装置定值。除能用于差示扫描量热仪(DSC)在-57℃、28℃、426℃及573℃区域的温度校准或检定外,还可用于热机械分析仪     

全国化工标准物质委员会标准物质研究开发中心

<正>国防科技工业应用化学一级计量站差示扫描量热仪温度检定/校准用系列标准物质[GBW(E)130174-130177]该系列国家标准物质由正辛烷、正十八烷、硫酸银、石英砂组成。采用高精度凝固点测量装置和相变温度测量装置定值。除能用于差示扫描量热仪(DSC)在-57℃、28℃、426℃及573℃区域的温度校准或检定外,还可用于热机械分析仪(TMA)、热膨胀仪及动态热机械分析仪(DMA)在相应温区的温度校准。该系     

标准物质信息

国家技术监督局“技监量函(1994)004号”通知,批准了17种国家二级标准物质,并统一编号,核发了“国家标准物质定级证书”和“制造计量器具许可证”。其中五种是由国防化学计量一级站研制的,这五种标准物质分别是: GBW(E)130120介质膜干涉滤光片标准物     

标准物质与分析测试 Ⅲ.标准物质的研制

本讲介绍标准物质研制过程中的四个重要步骤:制备;均匀性检查;定值;稳定性考察等。通过实例说明应用统计检验进行数据处理的方法。一、制备标准物质种类繁多,各类标准物质的制备方法各异。例如冶金标准物质通常经过配料、熔炼、铸造、     

国防科技工业应用化学一级计量站 全国化工标准物质委员会标准物质研究开发中心标准物质目录

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国防科技工业应用化学一级计量站 全国化工标准物质委员会标准物质研究开发中心 标准物质目录

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标准物质的制备

介绍标准物质候选物的选择与标准物质的制备要求。     

仪器分析标准物质

简述仪器分析标准物质的重要性及我国发展现状，指出了仪器分析标准物质研制中存在的问题。以光谱分析标准物质为例，介绍了仪器分析标准物质研制的特点，光谱分析标准物质的均匀性是研制的关键，其标准不确定度应由定值分析产生的标准不确定度、块状样品间的不均匀性产生的标准不确定度及块状样品内部的不均匀性产生的标准不确定度组成。     

国际标准化组织标准物质委员会

国际标准化组织(ISO)指南30中,标准物质(RM)的定义是:“具有一种或多种足够均匀和很好确定了的特定值,用以校准设备、评价测量方法或给材料赋值的材料或物质”。在现代社会的科学与技术活动中,它已成为必不可少的组成部分。在过去数十年里,各个国家都纷纷研制各自的标准物质以满足其工     

Certified reference material (CRM 414) for the quality control of trace element analysis in plankton

Summary Analyses of plankton are performed by a number of organisations to investigate the transfer and uptake of toxic elements along the trophic chain and to monitor the levels of contamination of different aquatic environments. In order to obtain reliable transfer functions in environmental models or to use plankton as an indicator organism for the assessment of environmental pollution, these analyses should give accurate results. As accuracy requires quality control and the application of certified reference materials (CRMs), a certification campaign has been conducted by the Community Bureau of Reference (BCR). A plankton material was collected in a freshwater pond, lyophilised, homogenised and bottled and its homogeneity and long-term stability were verified. The material (CRM 414) was analysed by a group of 15 selected laboratories having given proof of their adequate QC and using different analytical methods. The contents of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Se, V and Zn are certified. This paper presents the certification work performed.     

Certified reference material (CRM 397) for the quality control of trace element analysis of human hair

Summary Analyses of human hair are routinely performed by a number of organisations to monitor the level of exposure of a population to toxic elements, e.g. heavy metals. To control the quality of such determinations, the Community Bureau of Reference (BCR) has produced a reference material (CRM 397) certified for its contents of Cd, Hg, Pb, Se and Zn. This material was collected in a moderately contaminated area, carefully prepared and its homogeneity and long term stability were verified. This paper presents the certification work performed.     

Certified reference material for the determination of perfluorooctane sulfonate in acrylonitrile-butadiene-styrene resin (NMIJ CRM 8155-a)

A certified reference material (CRM) for the determination of perfluorooctane sulfonate (PFOS) in acrylonitrile-butadiene-styrene (ABS) resin (NMIJ CRM 8155-a) has been issued by the National Metrology Institute of Japan (NMIJ). The bulk material was prepared by mixing commercial ABS resin powder and potassium PFOS and cut into square plates (20 × 20 mm, 2 mm thick) as the CRM. Analytical processes combined with isotope-dilution mass spectrometry and liquid chromatography/mass spectrometry were optimised and applied for characterisation. One of the approaches adopted by NMIJ for certification is that results from two or more primary methods of measurement should be used; thus, two optimised isotope-dilution mass spectrometric methods (Methods 1 and 2 with reprecipitation and with reprecipitation/solid phase extraction, respectively, were validated mutually and employed) were used to determine the certified value. Homogeneity and stability of the square plates were evaluated and their uncertainty contributions (as relative standard uncertainties) were 1.43% for inhomogeneity and 6.96% for approximately two years’ instability. The certified mass fraction of linear PFOS (heptadecafluoro-1-octanesulfonic acid) in the CRM with expanded uncertainty (coverage factor k = 2, approximately 95% confidence interval) was (33.1 ± 5.0) mg kg^?1 as free acid of PFOS.     

分析用标准样品氟铃脲的合成、纯化及表征

合成了氟铃脲农药粗品,通过活性炭吸附、重结晶进行初步纯化;然后采用柱层析分离技术,以硅胶为填料,乙酸乙酯／石油醚（30～60℃）（1：3,V／V）为展开剂（Rf≈0．5）进行提纯。用紫外光谱（UV）、红外光谱（IR）、核磁共振（^1H NMR,^13C NMR）及质谱（MS）进行了结构表征;以高效液相色谱法测得该试样纯度在99％以上。     

Certified reference material for the quality control of EDTA- and DTPA-extractable trace metal contents in calcareous soil (CRM 600)

Single extraction tests are commonly used to study the eco-toxicity and mobility of metals in soils, e.g. to assess the bioavailable metal fraction (and thus to estimate the related phyto-toxic and nutritional deficiency effects) and the environmentally accessible trace metals upon disposal of e.g. sediment on to a soil (e.g. contamination of ground waters). However, the lack of uniformity in the different procedures does not allow the results to be compared worldwide nor the procedures to be validated. This paper describes the interlaboratory testing of EDTA- and DTPA-extraction procedures for soil analysis, followed by the preparation of a calcareous soil reference material (CRM 600), the homogeneity and stability studies and the analytical work performed for the certification of the EDTA- and DTPA- extractable contents of some trace metals (following the standardized extraction procedures). Received: 21 May 1997 / Revised: 4 July 1997 / Accepted: 9 July 1997     

Certified reference material for the quality control of EDTA- and DTPA-extractable trace metal contents in calcareous soil (CRM 600)

Single extraction tests are commonly used to study the eco-toxicity and mobility of metals in soils, e.g. to assess the bioavailable metal fraction (and thus to estimate the related phyto-toxic and nutritional deficiency effects) and the environmentally accessible trace metals upon disposal of e.g. sediment on to a soil (e.g. contamination of ground waters). However, the lack of uniformity in the different procedures does not allow the results to be compared worldwide nor the procedures to be validated. This paper describes the interlaboratory testing of EDTA- and DTPA-extraction procedures for soil analysis, followed by the preparation of a calcareous soil reference material (CRM 600), the homogeneity and stability studies and the analytical work performed for the certification of the EDTA- and DTPA- extractable contents of some trace metals (following the standardized extraction procedures). Received: 21 May 1997 / Revised: 4 July 1997 / Accepted: 9 July 1997     

Effect of ultrasound agitation on the release of heavy elements in Certified Reference Material of human hair (CRM BCR 397)

An ultrasonic-assisted leaching procedure was developed for the determination of heavy elements (As, Cu, Cd, Pb, and Zn) in Certified Reference Material of human hair (CRM 397) provided from the Community Bureau of Reference (BCR) of the Commission of the European Community. Concentrated nitric acid-30% hydrogen peroxide (2 + 1) was used for the leaching method. The effects of different factors on acid leaching of elements, such as presonication time (without ultrasonic stirring), sonication or exposure time to ultrasound, and temperature of the ultrasonic bath have been investigated. Optimum values of these parameters were selected for the maximum extraction of heavy metals from CRM BCR 397 and human scalp hair samples of normal healthy males. To check the validity of the proposed method, a wet acid digestion method was used to obtain the total elemental concentration in CRM BCR 397 and scalp hair samples. Cu and Zn in leachate and digests were measured by flame atomic absorption spectrometry using a conventional air/acetylene flame, while As, Cd, and Pd were determined by electrothermal atomic absorption spectrometry. Under optimized conditions, the recovery for Zn, Cd, Pd, As, and Cu was 98, 98.5, 97.5, 98.2, and 95%, respectively, of those obtained with the wet acid digestion method.