镉标准溶液配制结果的不确定度评定

选择氧化镉标准物质,配制成质量浓度为1000μg/mL的镉标准溶液,利用等离子体质谱法对标准溶液进行了定值与稳定性检验。通过对镉标准溶液配制过程不确定因素的描述,以95%概率下的扩展因子2获得标准溶液浓度配制标示值的扩展不确定度。实验数据表明,所配制的标准溶液稳定性可达2年。     

钛同位素标准溶液研制

钛同位素组成可用于地球化学和宇宙化学研究中,但目前国内外缺乏钛同位素标准物质.为了满足地质样品钛同位素分析的需要,本文研制了钛同位素标准溶液,报道了钛同位素标准溶液的研制过程和定值结果,包括标准溶液的选择、均匀性和稳定性检验、定值分析及测定数据的统计性检验等.通过初步测定,确定美国Alfa公司生产的Ti单元素溶液作为备选Ti同位素标准溶液.将备选标准溶液分装成150瓶,随机抽取15瓶进行均匀性检验,测试结果的F值均小于临界值,表明备选标准溶液的Ti同位素组成均匀.通过30个月的稳定性检验,标准溶液的特征量值变化在不确定度范围内.采用独家和多家实验室相结合的方法进行定值,标准溶液的特征量值及不确定度推荐为:δ50Ti=-2.23‰±0.14‰,δ49Ti=-1.67‰±0.09‰,δ48Ti=-1.13‰±0.06‰,δ47Ti=-0.57‰±0.05‰.研制的标准溶液可用于钛同位素分析时校正仪器和验证质谱分析过程,有利于不同实验室的测试数据之间的对比和应用.     

地下水中微量元素实验室际分析结果准确度的探讨

地矿部门组织了七个实验室及研究中心,对实验室间现行分析方法的准确度,进行了考查。结果说明多数实验室分析结果是好的和比较好的,且不同实验室所报出的结果也是有可比性的。但也发现了一些值得引起重视的问题,有待于修订水质分析质量保证与质量管理规范,加以克服。 本次考查的内容包括:标准溶液、水样加入标准溶液的回收、水样分析结果的互检三项。     

异烟酸-吡唑啉酮分光光度法测定地下水中氰化物的不确定度评定

采用不确定度连续传递模型,对异烟酸-吡唑啉酮分光光度法测定地下水中氰化物的不确定度进行评定。分析了不确定度的重要来源,包括样品制备、标准溶液配制、标准曲线拟合和仪器测量过程等引入的不确定度分量。采用x、y双误差回归方式对标准曲线进行拟合,通过分析得知,样品中氰化物浓度越低,其相对不确定度越大。     

火焰原子吸收光谱法测定化探样品中铜结果不确定度评定

本文以火焰原子吸收光谱法对化探样品中铜的含量测定为对象,分析了测定不确定度的主要来源,包括样品称量过程、标准溶液配制、标准曲线拟合过程以及样品溶液定容过程,对各不确定度分量进行了分类与计算,评估了某化探样品的合成不确定度以及扩展不确定度.实验结果显示不确定度主要来自样品重复测量过程和标准溶液的配制过程.对于含量为35.05μg/g的土壤样品,其扩展不确定度为0.9744μg/g.     

X射线荧光光谱用人工标准物质的研制

使用高纯物质人工合成的方法,成功研制了4个人工标准物质。该系列标准物质涵盖了钛、钒、锰、铬、钴、镍、铜、锌、砷、铅、铋、铷、锶、钇、锆、铌、钼、钨、钕、钽、铪、镱、锡、钡、铯、镓、锗、镧、铈等29个元素,不同分析元素的含量范围可扩大到0.00x%~8%。该系列标准物质不仅可以补充自然标准的不足,扩展校准曲线含量范围,而且能够修正干扰系数,解决了准确计算分析元素之间的干扰和仪器校正带来的实际困难。用4个人工标准物质取代单元素人工标准的配制方法,减少标准数量,节约了资源以及标准配制的时间,避免了X射线荧光光谱分析工作者的重复劳动,提高了工作效率。研制的4个标准物质经检验均匀性和稳定性良好,量值准确可靠,已被国家质量监督检验检疫总局批准为国家一级标准物质。     

折射波时距曲线及解释剖面的自动绘制

本文提出并解决了折射波时距曲线及解释剖面的自动绘制问题。通过自动的绘制，输出美观、准确的时距曲线及解释剖面，避免了清绘等过程，节省了大量的人力、物力。     

水体中硫化物测定方法探讨

通过对测定硫化物标准曲线的质量保证及不同污染程度水样的前处理方法的探讨,得出硫化物标准溶液需现用现配及针对污染程度不同的水样分别采取直接测定、抽滤测定和酸化-吹气法测定的结论.     

称重法配制标准溶液研究及其不确定度评估

在标准溶液配制及稀释的过程中放弃了传统的定量移液管,采用精密电子天平作为定量工具。精密电子天平准确度高,重复性好,不需考虑溶液黏度、管口流速等因素对不确定度的影响,而且明显地降低了在标准溶液逐级稀释过程中由于读数、操作等原因产生的误差,可实现大比例稀释,操作简便。根据《化学分析中不确定度的评估指南》(CNAL/AG07:2002)评定了此方法与传统溶液配制方法的不确定度。利用电感耦合等离子体原子发射光谱法(ICP-AES)验证了其准确性和线性,均获得满意结果。本法适用于ICP-AES法测定样品中的主元素(含量在x%~xx%)时的标准溶液配制,也可应用于原子荧光光谱、原子吸收光谱等仪器系列标准溶液的配制。     

用于多接收器等离子体质谱测定的铁铜锌同位素标准溶液研制

近十来年铁铜锌同位素研究已经成为热门研究领域,铁铜锌同位素分析方法日趋成熟,但是铁铜锌同位素标准物质却十分匮乏。目前欧盟参考物质及测量研究所(IRMM)有1个铁同位素标准物质和1个锌同位素标准物质,前者售罄,后者价格昂贵;美国国家标准局(NIST)有1个铜同位素标准物质。为了适应我国铁铜锌同位素研究的发展,本文使用铁铜锌元素浓度标准溶液作为备选标准溶液研制了铁铜锌三个同位素标准溶液(CAGS-Fe、CAGS-Cu和CAGS-Zn)。三个备选标准溶液经过F检验均匀性良好;在38个月内δ56Fe、δ57Fe、δ65Cu、δ66Zn和δ68Zn值没有显著性变化,具有良好的稳定性;主要特性值的推荐值及95%置信水平的不确定度为:CAGS-Fe,δ56FeIRMM014(‰)=0.80±0.05,δ57FeIRMM014(‰)=1.20±0.10;CAGS-Cu,δ65CuIRMM976(‰)=0.57±0.06;CAGS-Zn,δ66ZnIRMM3702(‰)=-0.77±0.10,δ68ZnIRMM3702(‰)=-1.55±0.13。本文研制的标准溶液可用于多接收器等离子体质谱仪测定铁铜锌同位素时的仪器校正和质谱分析过程监控,对于不同实验室的测试数据对比具有重要意义。     

The Development of Laser Ablation ICP-MS and Calibration Strategies: Examples from the Analysis of Trace Elements in Volcanic Glass Shards and Sulfide Minerals

This contribution presents a review of the recent developments in laser ablation inductively coupled plasma-mass spectrometry. We describe the important developments which have occurred in the laser systems used, leading to a spatial resolution of around 20 (im, and give an overview of the major instrument developments which have affected the geological applications of laser ablation ICP-MS. We describe the calibration of laser ablation for the analysis of trace elements in two different matrices: volcanic glass shards and sulfide minerals. We show how single glass shards can be analysed using the National Institute of Standards and Technology (NIST) glass certified reference materials for calibration and demonstrate the effect of using single spot analyses compared to rastering of the calibration sample. We show the importance of inter-shard variation and demonstrate that averaged single shard analyses produce data which compare well with bulk analyses. The calibration of the laser system for sulfide mineral analysis is discussed and two different strategies are proposed, one using spiked pressed powder pellets of sulfides and the other metal reference materials. We present conclusions and recommendations for the calibration of laser ablation ICP-MS instruments.     

地质标准物质中痕量元素量值溯源性探讨

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。     

同位素地质样品分析的质量监控与质量评估

讨论了同位素地质样品分析的质量监控与质量评估问题,提出在同位素地质样品分析中以准确度与精度度并重、标准物质监控与重复样监控相结合的质量监控方法。通过对大量标准样品定值数据与积累的测试数据的统计分析,提出了标准物质测定误差和标准偏差及重复样双份分析的双差允许限的确定方法,并采用准确度分数、精密度分数、空白分数和系统性偏倚分数对测试结果的质量进行定量评估的方法,这些方法适用于实验室内部的质量监控和评估     

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.     

Excel在水质分析标准曲线及回归方程截距检验计算中的应用

在水质分析标准曲线及回归方程截距检验的统计计算工作中,为解决日常工作中经常遇到的计算容易出错、各种计算方法及过渡数据有效位数的人为取舍对计算结果的一致性影响较大等问题,就如何应用计算机Excel计算模板快速准确地完成上述有关计算工作进行探讨;阐述了应用Excel计算模板的方法原理,介绍了计算模板的建立、验证、应用、保存、借用等实用经验;在相关计算工作的快速准确及提高工作效率等方面得到了满意的结果。     

Forty‐Nine Major and Trace Element Concentrations Measured in Soil Reference Materials NIST SRM 2586, 2587, 2709a, 2710a and 2711a Using ICP‐MS and Wavelength Dispersive‐XRF

Excellent agreement was noted in the concentration of major and trace elements in five NIST (National Institute for Science and Technology) soil reference materials (NIST SRM 2586, 2587, 2709a, 2710a and 2711a) between measurement results from wavelength dispersive‐XRF and ICP‐MS from two independent laboratories, and NIST certificate of analysis and literature data. We describe the variability in concentrations of up to forty‐nine elements (plus loss on ignition) and provide values for up to twenty‐one elements previously uncharacterised by NIST in these soil RMs. The additional characterisation provided in this investigation can be utilised to reduce the measurement bias of custom calibration routines and improve the quality of control checks developed using these NIST RMs.     

中国与世界铂族元素地球化学标准物质评介

铂族元素分析一直是地质材料分析中最棘手的任务之一,是铂族金属矿产资源勘查、评价和相关研究工作的瓶颈。铂族元素标准物质作为铂族元素分析的计量标准,在分析质量监控、分析仪器校准、分析方法评价和仲裁分析中发挥着重要作用。笔者等评介了我国研制的超基性岩和铬铁矿铂族元素标准物质、铂族元素地球化学标准物质、铂族元素矿石标准物质和海山富钴结壳铂族元素标准物质共4个系列21个标准物质,也给出了其他地球化学标准物质中铂族元素的定值数据;并与南非、加拿大、俄罗斯和岩石矿物分析标准国际工作组(GIT-IWG)研制的13个铂族元素标准物质及其他国际地球化学标准物质中铂族元素的数据进行了对比。这些标准物质的研制与应用将大大提高铂族元素分析数据的可靠性,为我国和世界铂族金属矿产资源勘查、评价及研究提供了有力的技术支撑。     

重力式挡土墙质量检测与安全评估方法

重力式挡土墙以其构造简单,取材方便,工程造价经济等诸多优点被广泛应用于建筑、交通等领域,而如何鉴定挡土墙的综合质量是挡土墙检测的主要问题。通过参考大量的工程实例和工程经验,针对挡土墙检测过程中提出了一套合理的、科学的检测步骤和检测方法,并结合挡土墙的稳定性验算和安全验算,对检测数据进行系统的分类和评估,最后得到了一套针对挡土墙综合质量的安全评估标准,将挡土墙的综合质量进行评级,以便科学地指导工程加固。     

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.     

Preparation of Synthetic Calibration Materials for Use in the Microanalysis of Oxide Minerals by Direct Fusion in High-Purity Graphite Electrodes: Preliminary Results for Quartz and Rutile

This paper describes a technique for the preparation of synthetic calibration materials for use in laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) and other microtechniques for mineral analysis. The method is based on direct fusion in high-purity graphite electrodes, and the requisite temperatures for melting are obtained by resistance heating using a welding rectifier as the power source. The technique has been tested on quartz (SiO₂) and rutile (TiO₂) for a relatively large range of elements, including all the rare earth elements. Different starting materials for preparation of calibration materials were studied, and it is shown that many natural materials form separate phases during fusion, resulting in unusable calibration materials for microanalysis. However, calibration materials prepared fully synthetically from oxides and/or element nitrates in solution were found to be of good homogeneity, and this preparation technique was used throughout in this work. The quality of the calibration materials for quartz and rutile was assessed by LA-ICP-MS, using Si and Ti as internal standard elements respectively. The NIST SRM 612 and 614 glass standards were used to assess the accuracy of the calibration materials for quartz. Calibration curves based on two independently prepared sets of calibration materials and the two NIST glasses are shown for a number of elements, demonstrating excellent agreement between the NIST glasses and the synthetically prepared quartz glasses. Vesicles are shown to form in the SiO₂ glasses, but this does not influence their value as calibration materials, provided that a reference element is used as an internal standard. The advantages of fusion in high-purity graphite electrodes are emphasised, particularly the very high sublimation point of graphite, its very high state of purity, the very short melting and quench time, the speed and simplicity of the method, and the low risk of introducing impurities. Extension of the method to other minerals and applications is discussed.