1993 COMPILATION OF DATA ON FIVE BELGIAN SEDIMENTARY ROCK REFERENCE MATERIALS: AWI-1, SBO-1, PRI-1, CCH-1 AND DWA-1

Five Belgian sedimentary rock reference materials have been prepared and distributed by the Geology, Petrology and Geochemistry Laboratory (Liège University, Belgium). Thirty-six laboratories participated in the international co-operative study. The individual data received from the participating laboratories are listed. Tables of compiled results are presented for major, minor and trace elements. These updated values are summarized into means, associated standard deviations, medians, and concentration ranges. "Recommended" (or proposed) values are presented.     

Report of the International Association of Geoanalysts on the Certification of Penrhyn Slate, OU-6

The International Association of Geoanalysts (IAG) has certified a slate sample, OU-6, for twelve major and minor constituents, as well as thirty-five trace elements through an interlaboratory programme conducted in close compliance with the International Organization for Standardization (ISO) Guide 35 (1989). Laboratories were qualified for participation in the certification programme, based on their performance in the prior analysis of OU-6 as a proficiency test material. Thirty laboratories provided data for the certification, though not for each constituent that was certified. Certification criteria included a means of establishing traceability for the certification data, generally through concurrent analysis of the existing Geological Survey of Japan reference material JSl-1, agreement of results between laboratories and methods, and a minimum of data rejection (4% rejection rate for OU-6 data and 6% for JSl-1 data), preferably for well-understood technical reasons only. Information values are provided for an additional eight constituents where certification criteria were not met. Uncertainties developed in accordance with the "Guide on Uncertainty in Measurement" (Eurachem 2000) and representing the 95% confidence interval of the certified and information values are reported for all fifty five constituents. The material is currently available in 40 g units for distribution by the IAG. Supply is anticipated to last about ten years.     

International Association of Geoanalysts' Protocol for the Certification of Geological and Environmental Reference Materials: A Supplement

The International Association of Geoanalysts (IAG) published a protocol for the certification of reference materials in close accord with the International Organisation for Standardisation (ISO) guidelines (Kane et al. 2003). This article supplements that protocol, providing additional discussion of best approaches for pre-selecting laboratories for participation in certification projects. This discussion also makes a distinction between inter-laboratory certifications, where n = 15 is the general standard, and expert laboratory certifications, where a much smaller number of laboratories will be deemed qualified to provide data of the quality needed for certification.     

PRAGMATISM vs RIGOUR: A Debate on the Resolution Of Disparate Analytical Data on Four Canadian Iron - Formation Reference Samples

The analytical data received in an inter-laboratory study of four Canadian reference samples were treated by two different methods in order to arrive at "usable values" for the concentration of each constituent. The first method ("Select Laboratories"), proposed by S. Abbey (S.A.), is based on the fact that some laboratories consistently produce better results than others. S.A. suggests an approach which permits isolation of results from such laboratories, calculation of a mean or a median of such results and use of one or the other as the concentration of a constituent. That approach involves a degree of subjectivity and S.A. attempts to demonstrate the validity of his approach by means of several tests applied to the results obtained for the four samples.     

G-Probe-1 - An International Proficiency Test for Microprobe Laboratories - Report on Round 1 : February 2002 (TB-1 Basaltic Glass)

Results are presented for round one of a new international proficiency testing programme designed for microprobe laboratories involved in the routine analysis of silicate minerals. The sample used for this round was TB-1, a basaltic glass fused and prepared by the USGS. Thirty nine laboratories contributed data to this round, the majority of major element results being undertaken by EPMA and the majority of trace elements by LA-ICP-MS. Assigned values were derived from the median of results produced by nine selected laboratories that analysed powdered material by conventional ICP-MS, INAA and XRF techniques using bulk powders of the sample. Submitted microprobe results were evaluated using a target precision calculated using the Horwitz function, adopting the same criteria as those used for "applied" geochemistry laboratories in the companion GeoPT proficiency testing programme for laboratories involved in the routine bulk analysis of silicate rocks. An evaluation of results from participating microprobe laboratories indicated that overall, data were compatible with this precision function. A comparison between the performance of bulk and microprobe techniques used in the analysis of the basaltic glass showed remarkably good agreement, with significant bias only observed for the major oxide MgO.     

河南三门峡市实验室“三废”污染情况初探及思考

分析了实验室“三废”污染的现状、分布、数量、种类、;建议本着科学选择方法,节约使用试剂,适当处理和回收利用的原则来处理“三废”;强调“谁污染,谁治理”是化学工作者义不容辞的职责。     

地下水污染调查中水样无机组分检测质量控制体系 的建立和应用

实验室分析全过程的质量控制,其目的是将检测误差控制在容许限度内,以保证数据在给定的置信水平内达到质量要求。国土资源部天津矿产资源监督检测中心根据地质矿产行业标准DZ/T0130—2006《地质矿产实验室测试质量管理规范》、DD2008—01中国地质调查局标准《地下水污染调查评价规范》,并参照其他行业对水质分析质量控制要求,结合水质检测的具体情况,制定了适宜的地下水分析过程的质量控制体系,使实验室质量控制和质量管理具有良好的操作性和可行性,确保检测数据的可靠性。文章从5个方面提出地下水水质无机组分检测中质量控制方法,使水质无机组分的检测质量得到有效控制。     

New Reference Material of Dunite Rock, NGRI-UMR: Preparation and Evaluation

A dunite reference material has been prepared as part of the reference materials programme at the National Geophysical Research Institute, Hyderabad, India. The scarcity of reference materials for undertaking the chemical analysis of ultramafic rocks for major and trace elements justified the preparation of such a rock reference material. A 300 kg sample of starting material was collected from an active quarry near the town of Salem in Tamil Nadu, southern India. The sample was homogenized and an invitation for round robin participation was published in Geostandards Newsletter (October 1995). A total of twenty seven international laboratories participated in the study, providing information on the total element concentration of major, minor, trace and rare earth elements. Following data compilation, outlier rejection, and statistical analysis, proposed and indicative total element concentrations are reported for twenty four elements.     

The Search for "Best Values"- A Study Of Three Canadian Rocks

A comparison is made between various measures proposed thus far for deducing the "best values" from discordant data received in the course of collaborative analysis of proposed reference rocks. Using the raw data on three Canadian samples and the summation and "iron-oxide compatibility" tests, it is claimed that the "select laboratories" method produces the best results.     

An Evaluation of USGS III

"Usable values" based on evaluation by the "select laboratories" method are presented for concentrations of many constituents of eight reference rocks from the U.S. Geological Survey. Comparisons are made between the derived values and those published earlier.     

Report (1980) on Three GIT-IWG Rock Reference Samples: Anorthosite from Greenland, AN-G; Basalte d'Essey-la-Côte, BE-N; Granite de Beauvoir, MA-N

Three rock reference samples, Anorthosite AN-G, Basalt BE-N and Granite MA-N were analysed for their chemical composition by 122 laboratories belonging to the International Working Group "Analytical Standards of Minerals, Ores and Rocks" (IWG). 243 analysts took part in this first collaborative study which lasted only nine months, from June 1979 to March 1980. Despite this very short period, it has been possible to harvest over 6000 units of analytical data on major, minor and 53 trace elements. This excellent performance of the IWG members has rendered possible the chemical characterization of the three samples for not only the usual major and minor elements but also for 30 trace elements. This first study by the IWG Members demonstrates well their immense analytical potential and is exemplary in many respects.     

Analytical Data on Three Rock Reference Samples from the Institute of Geochemistry, Irkutsk, USSR

Analytical data obtained in our two laboratories on three rook samples from the Institute of Geochemistry, Irkutsk, are reported and compared with "established", "certified" and "uncertain" values. Methods used are described briefly and some comments offered on earlier published information.     

1994 REPORT ON WHIN SILL DOLERITE WS-E FROM ENGLAND AND PITSCURRIE MICROGABBRO PM-S FROM SCOTLAND: ASSESSMENT BY ONE HUNDRED AND FOUR INTERNATIONAL LABORATORIES

This compilation report describes the field location, mineralogy, preparation and homogeneity testing of two new GIT-IWG reference materials: Whin Sill dolerite (WS-E) from England and Pitscurrie microgabbro (PM-S) from Scotland. The elemental composition of these two new reference materials has been established by an international cooperative analysis programme involving participation by 104 laboratories. A full assessment of these analytical results is presented, from which working values have been derived for the major elements as well as for 45 trace elements in WS-E and 44 trace elements in PM-S. Furthermore, isotopic ratios are presented for both samples, particularly for ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd.     

Preparation and Characterisation of Two Geochemical Reference Materials: DG‐H (Granite) and AM‐H (Amphibolite) from the Himalayan Orogenic Belt

Two geochemical reference materials of Himalayan origin named DG‐H (a granite) and AM‐H (an amphibolite) prepared by the Wadia Institute of Himalayan Geology Dehradun are described. Both samples were collected from the NW Himachal Himalaya in India. With the participation of analysts from more than forty international laboratories, element determination data collected during the past 10 years for characterisation of the samples was processed to assign working values using statistical procedures in use for this purpose. Earlier work published on these samples is incorporated in the present communication making it an updated document. The typical chemical and petrological characteristics of these two samples may prove useful for method validation and calibration of analytical instruments used for analysing similar rock types, and for widening the analytical range of several analytical methods used for geochemical analysis.     

北祁连黑矿型和塞浦路斯型硫化物矿床容矿火山岩的物质来源与形成环境

文章以白银厂石英角斑岩和石居里富钠玄武岩为代表,对产于北祁连造山带的"黑矿型"和"塞浦路斯型"铜多金属块状硫化物矿床的容矿火山岩做了系统的常量元素、微量元素、稀土元素及锶、钕、铅同位素分析。结果表明,这2种火山岩均表现出俯冲带岩浆作用的特征。所不同的是,白银厂"黑矿型"块状硫化物矿床容矿火山岩形成于活动大陆边缘的陆缘弧环境;石居里"塞浦路斯型"硫化物铜矿床形成于大洋板块内部的洋生弧环境。与各自的形成环境相对应,白银厂的石英角斑岩来源于原生地幔在俯冲板片流体参与下的部分熔融,岩浆在上升侵位过程中有部分大陆地壳物质混入。石居里的富钠玄武岩同样也是产生于原生地幔在板片流体作用下的部分熔融,但没有遭受陆壳物质混染。     

KOMATIITE WITS-1, LOW CONCENTRATION NOBLE METAL STANDARD FOR THE ANALYSIS OF NON-MINERALIZED SAMPLES

WITS-1 is a sample of silicified komatiite collected from close to the Komati River type section, near Barberton in South Africa. Two thousand kg of this komatiite was crushed and prepared for standardization. Noble metal analysis of WITS-1 has been carried out by six laboratories using four different analytical methods. The data obtained from these sources were subjected to statistical analysis (F ratio and Student t test) and a suite of "preferred" values for the noble metal concentrations are reported.     

SERMIN1 and VIDAC18: Two Proposed Reference Materials for Rare Earth Element Determination in Groundwater

In this work, homogeneous samples of two Portuguese mineral waters, SERMIN1 and VIDAC18, have been analysed for their REE contents. The participation of twenty international laboratories made it possible to evaluate the data by robust statistical procedures. Eighty-one percent of the participants used ICP-QMS for REE determination in these two candidate reference materials. Assigned values are reported for SERMIN1, covering the fourteen naturally occurring lanthanides (La-Lu). For VIDAC18, assigned values are presented only for ten REE, since accurate assigned values for La, Ce, Tb and Eu need further analytical work to improve data quality.     

Role of Statistics in the Certification Of Standard Reference Materials

Caimon practice indicates that measurements made in different laboratories on the same material (chemical analyses, for instance) can vary considerably. The differences can be ignored as long as their amplitude is of little practical significance, but in many cases, they cannot be disregarded and may even become a problem.
If the material is intended for use as a reference material, the results obtained by various laboratories have to be treated to produce a "certified" value. The choice of the appropriate method of treatment depends on basic philosophical views about the nature and the structure of the scatterain the results. Statistical methods provide the correct answer when the fluctuations involved can be regarded as random.     

Geochemical Reference Samples, Drainage Sediment GSD 1 - 8 from China

A set of eight geochemical standard reference samples of stream sediments was prepared. The original purpose was to use these samples as primary standards for the data quality monitoring of a nation-wide regional geochemical survey program in China. But their use has been soon extended to other fields. Forty-one laboratories in China have joined in a collaborative venture to analyse these samples, using a variety of analytical procedures. Recommended values for over 50 trace and minor elements were derived by a method of repetitive elimination of outliers and calculation of central "tendency" from several central values.