地质标准物质均匀性检验方法评介与探讨

评介了目前中国地质标准物质研制中样品均匀性检验与评价所用方法,包括:检测方法,统计判别模式,结果的定性、定量表达和最小取样量确定等。对照国家相关技术规范、国际标准化组织导则和国际地质分析者协会的地质标准物质定值协议,探讨了我国地质标准物质均匀性检验与评价中的难点及现存问题。     

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。     

地质标准物质的粒度测量与表征实践

样品粒度是粉体地质标准物质的一项重要特性指标。长期以来地质标准物质的粒度一直是采用筛分法或沉降法检测,最终大多以加工样品通过一定筛目(一般为-200目)的比例来表达;近年来超细标准物质研制引入了以激光粒度仪为代表的粒度检测与分析的现代方法,并可以直观的粒度分布图和简洁明晰的特征粒径等多种方法来表达粒度分布特征,大大提升了粉体地质标准物质粒度分布特性的测量及表征水平。文章在前期采用激光粒度仪测量超细标准物质粒度分布特征工作的基础上,用此法测量了当今广泛使用的典型地质标准物质的粒度分布,为这些标准物质的正确使用和取样不确定度评价提供了重要依据;同时就今后地质标准物质乃至地质分析样品的粒度检测与表征提出建议。     

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。     

地质标准物质粒度测量与表征的现代方法

地质标准物质是地质材料分析的计量标准,在分析质量监控、仪器校准和分析方法评价中发挥着重要作用。地质标准物质大多为粉体材料,而粒度是粉体材料的一项重要特性指标。长期以来,地质标准物质的粒度一直采用过筛法检测;近年来在超细标准物质研制中引入了以激光粒度仪为代表的现代粒度分析方法,并以直观的粒度分布图和简洁的特征粒度来表达分析结果,大大提升了粉体地质标准物质粒度特性的测量及表征水平。在此工作基础上,测量了正在广泛使用的典型地质标准物质的粒度分布,获得了前所未知的粒度分布信息,为这些标准物质的正确使用和取样不确定度评价提供了有益的资料。简单地介绍了检测粉体材料颗粒特性的现代方法,讨论了地质分析与粒度分析在概念上的差异,并就今后地质标准物质乃至地质分析样品的粒度检测与表征方法提出了建议。     

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...     

关注地质分析文献,了解分析技术发展——地质分析技术应用类评述论文评介

地质分析技术产生的数据是进行地质科学研究和矿产资源、地质环境评价的重要基础,是发展国土资源地质调查事业和地球科学的重要技术支撑。中国地质事业已经得到了空前的发展,地质分析文献迅速增加,迫切需要对文献进行整理、加工、综合、评价。为了解当前中国地质分析技术在各领域的应用状况和获得的成果,对国内科研人员20年来发表的地质分析应用类评述性论文作一评介,内容联系当今全球地质分析技术发展的新趋势,主要包括标准物质与标准方法,岩石矿物分析,地球化学调查（区域地球化学、多目标地球化学和生态地球化学调查）、地球化学填图样品分析,海洋地质样品分析,现场分析,贵金属分析,化学物相与元素形态分析,水分析,能源矿产和环境样品分析,稳定同位素和同位素地质年代学技术与应用10项分析技术领域取得的研究成果。阐述了国内地质分析技术新应用领域的进展、动态和发展前景。     

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.     

新生代透长石SK01作为39Ar-40Ar法定年标准物质的均匀性检验

39Ar-40Ar法定年分析过程中,对标准物质的需求有两个特点,一是需要将被测样品和年龄已知的标准样品同时放在核反应堆中进行快中子照射,标准样品的年龄直接参与被测样品年龄的计算;二是标准样品作为39 Ar-40 Ar法定年中的标尺,要求其年龄和被测样品年龄不宜相差太远,因此需要研制具有不同年龄值的标准物质用于分析不同时代地质样品.本文在研制新生代地质样品39 Ar-40 Ar定年标准物质过程中,通过综合研究,选定了可可西里风火山超浅成石英斑岩中的透长石SK01作为候选标准矿物,按照规定对其39 Ar-40Ar年龄值(特性量值)进行均匀性检验.统计结果显示,特性量值的F值为0.857,小于F临界值2.08,相对标准偏差为0.66％,远小于规定的5％范围,证明本批样品的均匀性良好,符合国家一级标准物质技术规范(JJG 1006-94)要求.模拟运输过程进行颠震试验,试验结果F值为0.00697,远小于F临界值6.59,其相对标准偏差为0.58％,远小于规定的5％范围,证明样品在运输过程中颠震对其均匀性无影响.最小取样量试验表明,在目前的实验条件水平下,为保证标准物质作为准确的年龄标尺的作用,透长石SK01的39 Ar-40 Ar年龄标准物质最小取样量为5 mg.综合检验结果表明,本批所选的新生代透长石SK01样品的均匀性良好,可以用于39Ar-40Ar年龄标准物质的定值分析.     

关注地质分析文献,了解分析技术发展——地质分析技术应用类评述论文评介

地质分析技术产生的数据是进行地质科学研究和矿产资源、地质环境评价的重要基础,是发展国土资源地质调查事业和地球科学的重要技术支撑。中国地质事业已经得到了空前的发展,地质分析文献迅速增加,迫切需要对文献进行整理、加工、综合、评价。为了解当前中国地质分析技术在各领域的应用状况和获得的成果,对国内科研人员20年来发表的地质分析应用类评述性论文作一评介,内容联系当今全球地质分析技术发展的新趋势,主要包括标准物质与标准方法,岩石矿物分析,地球化学调查(区域地球化学、多目标地球化学和生态地球化学调查)、地球化学填图样品分析,海洋地质样品分析,现场分析,贵金属分析,化学物相与元素形态分析,水分析,能源矿产和环境样品分析,稳定同位素和同位素地质年代学技术与应用10项分析技术领域取得的研究成果。阐述了国内地质分析技术新应用领域的进展、动态和发展前景。     

中国海洋地球化学探测技术的现状与发展

地球化学探测与分析技术在海洋地质调查、海底矿产资源勘探、研究与开发中发挥巨大作用，文中简介了我国目前海洋地球化学分析技术的现状，着重评介了用于海洋地球化学探测的一些新技术、新方法。主要包括：船载现场民探测技术；陆上实验室的现代分析方法以及用于化学数据质量监控、分析方法评价和进行国际对比的各类海洋标准物质的研制与应用。并结合前及近期我国海洋矿产资源与环境研究任务，对发展海洋地球化学探测与分析新技术提出建议。     

How Fit Are Your Data?

Most laboratories aim to produce data of the highest quality. Trying to lower uncertainties to infinitesimal figures and push detection limits even lower are valid goals. However, is it possible to overachieve? Are old data still of good enough quality to be usable? In a geochemical context, the main goal of producing analytical results is to answer geological or environmental questions. Not all scientific problems require the same data quality. What is really required are data of adequate quality – i.e., ‘fit-for-purpose’– to ensure that the geological problem at hand can be solved. Furthermore, it is doubtful that uncertainties and reproducibilities associated with field sampling are better than those from laboratories. It is thus proposed that, as geoanalysts, we encourage data users (students, colleagues or referees) to ensure that their analytical results are of sufficient quality to solve the problem. However, authors have to demonstrate, through the use of reproducibility testing, reference and quality control materials, that the quality of their results is sufficient to solve the problem. Uncertainties and detection limits in publications should not only be evaluated with respect to a set value, such as 10%, but also with regard to the geological problem to be solved.     

Precise Determination of Cadmium, Indium and Tellurium Using Multiple Collector ICP-MS

New sample preparation and ion-exchange separation methods as well as instrumental measurement protocols were established for the determination of trace-level Cd, In, and Te concentrations in geological materials by isotope-dilution mass spectrometry. High precision isotope ratio measurements were performed with a multiple collector inductively coupled plasma-mass spectrometer (MC-ICP-MS). The mass biases incurred for In and Te were corrected by adding and monitoring Pd and Sb standard solutions, respectively. Mass fractionation of Cd was corrected by using the mass fractionation factor calculated from the measurement of a standard solution. The measurement precision was better than 1 % for Cd, In and Te. Detection limits were < 1 ng g^-1 for Cd, < 0.02 ng g^-1 for In and Te. Using these new analytical techniques, the concentrations of Cd, In and Te were determined in six international geological reference materials. Concentrations could be reproduced within 3% for Cd, 4% for In and 10% for Te. Sample heterogeneity and volatility problems might have been the reason for the relatively large differences between Te replicates. Our results displayed excellent reproducibility compared with those of other techniques and agree well with data from previously published recommended values.     

地质调查通用标准物质及标准方法信息系统

根据各地质实验室的特点和质量管理规范需求，结合实验室认可及检测实验室能力的需要，建立了地质调查通用标准物质和标准方法信息系统。该系统不仅能提供地质调查通用标准物质、标准方法的基本信息，还增加了与能力分析相关的检测参数信息，并实现了标准信息网上查询和维护管理。该系统适用于地质调查实验室的质量管理系统。     

Total Sulfur Concentration in Geological Reference Materials by Elemental Infrared Analyser

Total sulfur is an analyte for which there are few determinations published, despite the fact that it is a very important element (e.g., a major element in most ores, an important gas constituent in global warming, an active participant in acid drainage). Most geological reference materials have very poor quality sulfur results, that is with relative standard deviations (RSD) in the range of 30–50%, even for concentrations over 100 μg g⁻¹ S, which compromises their use as calibrators. In order to provide modern results with low RSD, sulfur was determined in twenty-nine geological reference materials with a state-of-the-art elemental S/C analyser using metal chips (certified reference materials with a traceability link) and analytical grade sulfur for high concentration samples. Analytical parameters (sample mass, crucible degassing, calibration strategy, etc.) were optimised by testing. Our results agreed with reference material values provided by issuing bodies. Results for CCRMP SY-2 (129 ± 13 μg g⁻¹ S), which has been proposed as a sulfur reference material, were in agreement with the proposed modern value of 122 ± 3.7 μg g⁻¹ S.     

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.