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1.
Jean S. Kane 《Geostandards and Geoanalytical Research》2002,26(1):7-29
As in all fields of sample analysis, reference materials play a large role in supporting measurements in the geosciences. While a rather large number of materials are in distribution (> 380), not all are equally effective or fit-for-purpose in supporting laboratory data quality and thereby assuring the desired comparability of measurements between laboratories. Equally important, reference values that are not fit-for-purpose cannot be used effectively to establish traceability links between laboratory measurements and national and international standards. The needed fitness-for-purpose is not achieved for reference values either when more than one reference value has been proposed and a consensus does not exist among users as to which should be used by all, or when reference value uncertainties are too large in comparison to those of routine laboratory measurements. The focus of this review will be, first to outline the current reality, and second to suggest ways in which certifications of RMs can be improved to provide reference values that are universally accepted and more fit-for-purpose in general laboratory use. The discussion will be illustrated largely by current uses of USGS BCR-1, NIST SRM 610 and IAEA NBS28, as these three materials are those for which the largest body of newly published data exists, according to recent bibliographies of the geoanalytical literature published annually in Geostandards Newsletter: The Journal of Geostandards and Geoanalysis. 相似文献
2.
利用.NetCore的并行运算机制,实现基于Web的高性能地下管网的溯源分析功能。实践证明当某点管网数据监测出现异常时,能够快速分析所有可能流经该点源头管网信息,并在地图上动态展示分析结果,达到快速定位查询管网源头的区域管理目的。 相似文献
3.
JJG 2001-1987《线纹计量器具检定系统》是我国线纹计量器具进行量值传递的检定系统表,但其存在着许多不足,已无法满足当今计量检定的需要。此处对该检定系统表进行详细分析后给出修订建议,并介绍了目前国际上有关动向,提出了一些有益建议。 相似文献
4.
通过对世界辐射基准传递到我国省级工作级标准总辐射表的不确定度进行分析和评估,确定了量值传递过程中不确定度来源主要包括测量重复性、输出电压值、太阳入射角变化、热偏移以及标准器等引入的不确定度,得出我国省级工作级标准总辐射表校准结果的不确定度为0.6%。我国采用"成分和"法对省级太阳总辐射标准量值进行传递,其标准器引入的不确定度系标准直接辐射表(0.3%)和标准散射辐射表(1.0%)的合成,标准器引入的不确定度所占比例达90%以上,因此提高标准直接辐射和标准散射辐射的测量确定度是减小量值传递不确定度的关键。此外太阳辐射量值传递的准确性受天气条件的影响较大,选择天气稳定,大气透明度高的天气以及太阳高度角大于30°的时段;增加测量次数以减小测量数据的分散性,降低重复性测量引入的不确定度;对被校准总辐射表进行通风,以减小热偏移的影响;保证仪器安装水平以及准确跟踪遮光,可以进一步减小量值传递的不确定度,提高我国短波辐射的测量水平。 相似文献
5.
地质标准物质中痕量元素量值溯源性探讨 总被引：10，自引：4，他引：6
标准物质的特性量值应该具备溯源性。然而地质标准物质溯源性的建立往往是很困难的。对痕量元素量值溯源的若干难点进行了讨论;提出了建立标准物质研制的质量体系的建议并就相关问题进行了阐述;应重视量值的信息反馈,提高定值的质量。 相似文献
6.
麻痹性贝类毒素污染是世界共同关注和重点管控的食品安全问题, 其溯源一直是产业监管的难点和技术重点。基于指纹溯源技术理论, 采用室内模拟3种产毒藻暴露紫贻贝后风险形成过程, 开发基于超高效液相色谱-四极杆-静电场轨道阱高分辨质谱(UPLC-Q-Exactive MS)鉴定麻痹性贝类毒素区域特征的指纹溯源技术。结果表明, 采用乙腈/甲醇/丙酮(体积比为1︰1︰1)混合溶液作为提取剂, C8色谱柱联合正离子模式, 质荷比(m/z) 100~600和Amide色谱柱联合正离子模式, m/z 600~1 500作为色谱质谱检测条件下, 提取的化合物数量较多且稳定性良好, 覆盖了40.4%指纹信息; 紫贻贝与产毒藻中的共检出11种毒素成分, 且具有高度相关性。N-磺酰胺甲酰基类毒素(如C类)和膝沟藻毒素(GTX类)在暴露期发生了显著的代谢转化; 将摄食3种产毒藻后紫贻贝的差异化合物与特征毒素组分进行主成分分析及正交偏最小二乘法判别分析, 共筛选出13种复合指纹物质。构建6种特征物质的Fisher判别模型, 交叉验证准确率为88.9%, 可实现产毒藻种溯源。该研究建立了基于超高效液相色谱-四极杆-静电场轨道阱高分辨质谱UPLC-Q-Exactive MS紫贻贝特征指纹溯源技术, 初步实现了从污染麻痹性贝类毒素的贝类到肇事藻种的逆向溯源,可应用于贻贝麻痹性贝类毒素风险溯源研究。 相似文献
7.
古玉产地溯源研究对揭示文明早期玉石资源开发利用和跨区域物质、文化交流等都具有重要的意义。由于测试分析手段及研究样品本身的制约,古玉产地溯源至今仍然是制约古玉文化交流研究的难题及瓶颈。近年来,随着研究的深入及科学测试手段的进步,地质、考古及文博界开展了更为密切的跨学科合作,对古代玉器产地溯源技术进行了许多新的探索,并取得了一些较为重要的成果。本文在团队工作及前人研究的基础上,对质子激发X射线荧光(PIXE)、X射线荧光光谱(XRF)、激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)、电子探针(EPMA)等多种主微量元素地球化学分析测试技术及放射性同位素、稳定同位素地球化学技术在古代玉器产地溯源的应用情况进行了梳理,综合分析了不同测试方法在古玉溯源中的工作进展,并对当前古玉产地溯源研究中存在的问题进行了探讨。总体来说,岩矿地球化学分析测试技术的应用对古玉溯源研究起到了重要的推动作用,而对已知玉矿资源系统的地质学研究及玉料的主微量元素、同位素地球化学数据库的建设和新的无损、样品尺寸不受限的原位岩矿地球化学分析技术的开发及其在古玉样品测试中的大规模应用,应是未来古玉溯源研究工作的重点方向。 相似文献
8.
Ankam Durga Prasad Lori Rastogi Vinod Kumar Verma Vasudevan Krishna Kumari Sudhakar Yadlapalli Kulamani Dash 《Geostandards and Geoanalytical Research》2023,47(3):629-636
The National Centre for Compositional Characterisation of Materials (NCCCM) / Bhabha Atomic Research Centre (BARC) and National Aluminium Company Limited (NALCO), India have produced an Indian origin bauxite certified reference material (CRM), referred to as BARC-B1201, certified for major (Al2O3, Fe2O3, SiO2, TiO2, loss on ignition - LOI) and trace contents (V2O5, MnO, Cr2O3, MgO). Characterisation was undertaken by strict adherence to ISO Guides. A method previously developed and validated in our laboratory, using single step bauxite dissolution and subsequent quantitation (of Al2O3, Fe2O3, SiO2, TiO2, V2O5, MnO, Cr2O3 and MgO) by ICP-AES (SSBD ICP-AES) was used for homogeneity studies and an inter-laboratory comparison exercise (ILCE) of the candidate CRM. LOI was determined by thermo-gravimetric analysis. Property values were assigned after an ILCE with participation from seventeen reputed government and private sector laboratories in India. The CRM was certified for nine property values: Al2O3, Fe2O3, SiO2, TiO2, V2O5, MnO, Cr2O3, MgO and LOI, which are traceable to SI units. 相似文献
9.
太阳辐射测量标准仅采取定期参加国际比对的溯源方法不能完全满足质量保证的要求。只有联合国际比对和期间核查的控制方法,才能确保测量标准的测量不确定度持续控制在误差允许范围之内。我国太阳辐射测量标准与世界辐射测量基准 (WRR) 比对结果的不确定度为0.17%,满足世界气象组织 (WMO) 要求,并达到世界先进水平。为了保证在两次国际周期比对间隔之间的准确可靠,并保证其处于良好置信度的校准状态,定期对测量标准的重复性和稳定性进行期间核查, 以图形记忆方式对太阳辐射测量标准的测量过程进行连续和长期的统计控制。通过期间核查,保证了太阳辐射测量标准的重复性不大于0.1%,年稳定性小于0.25%,未超出控制界限且分布呈随机状态,保证了测量过程处于稳定受控状态,满足建标要求。 相似文献
10.
One or two gram aliquots of twelve reference materials with low platinum-group element (PGE) abundances (Ir concentrations ranging from 30 to 510 pg g-1 ) were analysed by isotope dilution ICP-MS using an on-line chromatographic matrix separation after acid digestion in a high pressure asher (HPA-S) to determine the concentrations of Ru, Pd, Re, Ir and Pt. Osmium concentrations were determined via ID-ICP-MS but as volatile OsO4 , whereas Rh concentrations were calculated by comparing the peak areas of the chromatographic peak with that of a standard solution. Validation of the method was performed and the concepts of traceability and measurement uncertainty were applied to assure comparability. The reference materials BCR-2, BHVO-1, BHVO-2, BIR-1, DNC-1, EN026 10D-3, MAG-1, RGM-1, SCo-1, SDO-1, TDB-1 and W-2 were investigated to test for their usefulness for certification. The use of TDB-1 is highly recommended because it is homogeneous at the two gram level and many values based on several different analytical procedures have been published. It is recommended that our efforts should focus on the certification of this reference material to reduce the uncertainties of its currently certified values (Pd and Pt only) and to assign certified values to the other PGE and Re. It is necessary to have at least one well-characterised RM for validation of methods applied to the analysis of PGE and Re in low abundance samples, although the matrix of TDB-1 might not completely match those of many samples. 相似文献