地质标准物质的研制方法

地质标准物质作为地质材料成分分析的计量标准,在分析质量监控、方法评价等方面发挥着越来越重要的作用.研制与应用地质标准物质是推动地质分析技术与方法发展必不可少的重要工作.通过介绍地质标准物质的研制过程和技术方法,重点讨论了地质标准物质的样品加工制备、均匀性检验、稳定性检验及定值等方面的标准要求及技术方法.     

中国地质标准物质制备技术与方法研究进展

评介了中国地质标准物质研制中技术方法方面的研究进展,包括样品加工技术,粒度检测与表征方法,均匀性检验与评价,最小取样量的确定,稳定性检验及其结果表述,定值方式,分析方法、数据处理及定值条件,不确定度评价与量值溯源保证等。对照国家相关的技术规范、国际标准化组织(ISO)的相关指南和国际地质分析者协会(IAG)关于地质标准物质研制的协议,讨论了目前中国地质标准物质制备技术的现状及未来的发展。     

中国地质标准物质文献(1980~2010)综述

评介了20世纪80年代中国首批地质标准物质诞生以来发表的有关地质标准物质的文献,包括:综合性评述,研制成果总结,样品加工、粒度检测、均匀性检测、稳定性检测评价、定值方式方法、不确定度评价、量值溯源等制备技术方法的研究与评述,研制工作的其它评述、专著等。最后对比了国内外地质标准物质的文献状况。     

中国地质标准物质研制进展

地质标准物质是保障地质样品分析结果准确性的重要基准。目前,一级地质标准物质数量居十三大类首位,形成了具有国际影响力的地质标准物质体系。本文依据基体类型和定值特性,将一级地质标准物质划分为基础、矿石、海洋、环境、能源和特殊用途等六类,总结了各类标准物质的研制数量、特点、定值指标、应用范围及意义。针对现阶段数量众多的地质标准物质在应用中还存在研制数量少、系列化不足、基体类型单一、定值指标少等问题,本文分析了不同类型存在的具体问题及产生的原因,探究研制技术成熟的地质标准物质中仍有多种成分难定值以及定值方法单一的可能原因,重点讨论了标准物质研制技术中影响定值水平的细节问题：(1)阐述了均匀性检验测量方法的优缺点,XRF法以其高精密度的优势应用于均匀性检验值得关注和研究;(2)提出了考虑元素性质、含量级次兼顾测试技术评定均匀性未检元素的不确定度评定方法;(3)分析了稳定性不确定度在总不确定度构成中成为主要贡献量的原因是当前的计算方法造成的,有待于进一步研究合理的评定方法;(4)建议针对不同类型标准物质,制定相对扩展不确定度控制限以获得准确可靠的标准值。结合当前地质标准物质存在的不足和工作需求,本...     

标准物质研制信息管理系统与合作平台

标准物质研制信息管理系统实现了对标准物质研制全过程如均匀性检验、稳定性试验、正态性检验、数据处理、标准物质定值、检测方法统计等原始数据及文档进行全方位综合管理.设计开发了项目管理、标准物质管理、用户管理、定值实验室管理、日志管理、稳定性试验、均匀性检验数据采集与统计处理、定值数据的采集与导入、定值数据离群值检验与处理、...     

大洋多金属结核及深海沉积物标准物质研制工作简述

简要介绍了太平洋多金属结核及深海沉积物标准物质研制中的总体设计、样品加工、均匀性检验、多实验室合作分析、数据处理以及最佳值确定。重点讨论了标准物质均匀性的定量评价与表达及其相应的测量方法。     

透辉石标准物质的均匀性检验及其相关问题的讨论

叙述了透辉石标准物质均匀性检验的方法和结果,确定了最小取样量。对标准物质均匀性检验中的有关问题进行了讨论。     

岩石标准物质均匀性的XRF检查法

长期以来岩石标准物质均匀性检查多系采用方差分析F检验作包装单元(使用单元)间的均匀程度一致性检验。这种检验以假定单元内物质分布均匀为前提,而对单元内物质分布是否足够均匀未作实际检验。本文主要探讨用XRF法作标准物质均匀性检查的一些问题。提出的方法不仅可对单元间的一致性、单元内的均匀性作方差分析F检验,而     

地质标准物质十年回顾

回顾了1992年以来国内外地质标准物质的主要情况。简单介绍了国际标准化组织在此期间颁布的有关文件。讨论了建立溯源性、均匀性检验等方面的一些问题。     

激光剥蚀电感耦合等离子体质谱元素微区分析标准物质研究进展

激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)是目前地球科学分析领域的重要技术手段,元素微区分析标准物质研制是该分析技术发展的重要方向。本文对当前LA-ICP-MS元素微区分析标准物质的种类、元素分布以及应用上的优缺点和标准物质的制备方法进行了评述。现有的有证标准物质数量不多、种类不齐全,部分元素浓度较低,定值不确定度较大,应用上受到较大的局限性;研制标准也不成熟,均匀性检验方面尚未有统一的方法。本文参照岩石粉末标准物质均匀性检验方法提出了两步均匀性检验法,同时指出在标准物质种类方面,铂族元素及Au元素浓度适当、Pb-S等不同硫化物基体标准物质,以及化学成分不同的碳酸岩和磷酸岩基体标准物质是当前的迫切需求;在标准物质研制技术方面,纳米岩石粉末压片技术的研发、原位微区分析标准物质(固体)均匀性检验判别标准研究是亟待解决的问题。     

Comparison of Synchrotron Radiation X-Ray Fluorescence with Conventional Techniques for the Analysis of Sedimentary Samples

A comparison is made of elemental analyses of sediment samples (lake bottom sediments and sediments from the petroliferous Bazhenovka Formation) by five competitive methods (synchrotron radiation X-ray fluorescence (SR-XRF), INAA, ICP-MS, AAS and traditional XRF). The object of this study was to identify the most suitable analytical techniques for applications in sedimentary geochemistry. Advantages and shortcomings of the five techniques were considered with respect to applications related to studies of palaeo-climate changes recorded in sedimentary cores from Lake Baikal and the geochemical stratigraphy of the Bazhenovka Formation, which is rich in organic material. We have concluded that SR-XRF was the best technique for producing extensive analytical data series, from the point of view of its speed, ease of application, cost, non-destructive nature and sensitivity, which allowed for the simultaneous determination of more than twenty elements of geochemical interest in small samples of sediments. An additional benefit of the method was demonstrated when used for the independent certification of geological reference materials. International reference samples BIL-1 and SDO-1 were certified by means of this method without use of reference materials. Analyses were based on the physics of the theory of energy transport.     

Homogeneity of the Geochemical Reference Material BRP-1 (Paraná Basin Basalt) and Assessment of Minimum Mass

Reference materials (RM) are required for quantitative analyses and their successful use is associated with the degree of homogeneity, and the traceability and confidence limits of the values established by characterisation. During the production of a RM, the chemical characterisation can only commence after it has been demonstrated that the material has the required level of homogeneity. Here we describe the preparation of BRP-1, a proposed geochemical reference material, and the results of the tests to evaluate its degree of homogeneity between and within bottles. BRP-1 is the first of two geochemical RM being produced by Brazilian institutions in collaboration with the United States Geological Survey (USGS) and the International Association of Geoanalysts (IAG). Two test portions of twenty bottles of BRP-1 were analysed by wavelength dispersive-XRF spectrometry and major, minor and eighteen trace elements were determined. The results show that for most of the investigated elements, the units of BRP-1 were homogeneous at conditions approximately three times more rigorous than those strived for by the test of "sufficient homogeneity". Furthermore, the within bottle homogeneity of BRP-1 was evaluated using small beam (1 mm²) synchrotron radiation XRF spectrometry and, for comparison, the USGS reference materials BCR-2 and GSP-2 were also evaluated. From our data, it has been possible to assign representative minimum masses for some major constituents (1 mg) and for some trace elements (1-13 mg), except Zr in GSP-2, for which test portions of 74 mg are recommended.     

中国地质标准物质研制和标准方法制定的成果与思考

简介了我国地质标准物质研制与标准方法制定的主要成果，重点讨论了其中在管理和技术方面值得思考的问题，并就提高我国地质标准物质水平，加速走向国际，提高国际影响力提出建议。     

Homogeneity testing of microanalytical reference materials by electron probe microanalysis (EPMA)

Homogeneity testing of candidate reference materials requires distinguishing the effects of measurement uncertainty of the analytical method from true compositional variations within the material. Many in situ microanalytical techniques do not allow classical ANOVA homogeneity testing due to the infeasibility of truly replicated analyses on the same analysis volume. This also applies to the analysis of beam-sensitive and light element-bearing materials by electron probe microanalysis (EPMA). This reality has led me to reconsider the homogeneity index approach used in the testing of microanalytical reference materials by EPMA. Based on statistical considerations, I show that the homogeneity index is suitable for statistical significance testing using F and chi-squared statistics and allows estimating the contribution of compositional heterogeneity to the total uncertainty budget of the referenced values. However, there are problems of bias and masking of small compositional variations by measurement uncertainty. This contribution shows the strong impact of the total number of measurements on the resolution of a microanalytical homogeneity study and discusses how to quantify the relative contribution of heterogeneity to the total uncertainty budget. I present an example of EPMA to illustrate this approach and show some pitfalls and limitations in its application.     

Study and Application of Geochemical Reference Materials in the Institute of Geophysical and Geochemical Exploration (IGGE), China

In order to meet the needs of geochemical mapping and geochemical exploration, 125 geochemical reference materials have been successively prepared by the Institute of Geophysical and Geochemical Exploration (IGGE) since 1978. They include certified reference materials of stream sediments (GSD1-14), soils (GSS1-16; ASA 1–6, for analysis of available elements), various rocks (GSR1-6, GSR13-15), biological material (GSV1-4 and GSB 1–10), synthetic silicates (GSES I 1–11) and limestones (GSES II 1–9 for spectral analysis). They also include geochemical reference materials for ore analysis: Cu-Pb-Zn ores (GSO1-4), Cu-Pb-Zn concentrates (GSO5-7), platinum-group element (PGE) ores (GPt5-6 and GPt9-10), silver ores (GAg1-6) and geochemical reference materials for Au (GAu8-14) and PGE determination (GPt1-4, and GPt7-8). A multi-laboratory collaborative analysis scheme was adopted in the certification procedure of the IGGE. Dozens of competent laboratories with hundreds of senior analysts in China participated in the certification analysis. These samples have been supplied to more than thirty countries and more than 4000 customers from national industrial, agricultural, environmental, scientific and educational fields. Most of the geochemical reference materials are used for the calibration of measuring apparatus, evaluation of analytical methods, certification studies, quality control and laboratory accreditation programmes.     

中国海及大陆架沉积物标准物质系列评介

自20世纪90年代末以来,在有关国家专项的支持下,中国先后研制了分别取自黄海、东海和南海的共9个大陆架沉积物地球化学标准物质,基本构成了一个比较有代表性的中国海及大陆架沉积物标准物质系列,为中国海洋国土及专属经济区调查研究工作提供了有力技术支撑.本文简介了这些标准的研制背景、概况,着重评介了这些标准物质的特点,特别说明了该标准物质系列在海洋地质调查与研究中应用及在地质分析技术发展上的意义.     

Reference Minerals for the Microanalysis of Light Elements

The quantitative determination of light element concentrations in geological specimens represents a major analytical challenge as the electron probe is generally not suited to this task. With the development of new in situ analytical techniques, and in particular the increasing use of secondary ion mass spectrometry, the routine determination of Li, Be and B contents has become a realistic goal. However, a major obstacle to the development of this research field is the critical dependence of SIMS on the availability of well characterized, homogeneous reference materials that are closely matched in matrix (composition and structure) to the sample being studied. Here we report the first results from a suite of large, gem crystals which cover a broad spectrum of minerals in which light elements are major constituents. We have characterized these materials using both in situ and wet chemical techniques. The samples described here are intended for distribution to geochemical laboratories active in the study of light elements. Further work is needed before reference values for these materials can be finalized, but the availability of this suite of materials represents a major step toward the routine analysis of the light element contents of geological specimens.     

长江三角洲沉积物标准物质研制

美国、加拿大等国家先后研制了10余个海湾和河口沉积物标准物质,但定值成分较少,大多侧重于有机污染物和放射性核素值。我国于2007年研制了3个黄河三角洲沉积物标准物质,为进一步满足近海地球化学调查及资源勘探的需要,本文按照ISO导则35和国家一级标准物质技术规范,研制了2个长江三角洲沉积物标准物质。按照不同粒径采集两个候选物样品,样品经干燥、球磨至200目,采用电感耦合等离子体质谱和发射光谱法进行均匀性检验,结果表明F实测值小于列表临界值F0.05(24,25)=1.96,样品均匀性良好。在两年时间内采用X射线荧光光谱法进行了4次稳定性检验,未发现统计学意义上的明显变化,样品稳定性良好。由12家有技术权威的实验室共采用13种准确、可靠的分析方法进行协作定值,最终定值元素53项,涵盖了主量、微量及全部稀土元素,其中主量成分含量呈梯度分布,如Al2O3的含量分别为16.42%、11.48%。该系列标准物质定值元素种类多,定值方法准确,能够为河口三角洲地区地质及环境调查的分析测试工作提供可靠的质量保证。