Recommended Radium-226 Values for Four CCRMP Uranium Reference Materials

The Canadian Certified Reference Materials Project announces recommended values for radium-226 activity in four reference materials previously certified for uranium. Thirteen laboratories participated in the interlaboratory program for DL-la, DH-la, BL-4a and BL-5. Four measurement techniques were applied. Procedural and instrument calibrations were performed with certified radium solutions from the National Bureau of Standards, thereby establishing traceability of the recommended values for radium-226 in DL-la, DH-la, BL-4a and BL-5. These reference ores are also shown to be close to, if not in, radioactive equilibrium.     

Uranium Tailings Samples UTS-1 to UTS-4 of CCRMP

The Canadian Certified Reference Materials Project announces the availability of reference uranium tailings sample UTS-1, -2, -3 and -4. Eighteen laboratories participated in the interlaboratory program for total iron, titanium, aluminium, calcium, barium, uranium, thorium, total sulphur, sulphate and arsenic. Eight laboratories participated in the inter-laboratory program for thorium-230, radium-226, lead-210 and polonium-210 in all four samples and for thorium-232, radium-228 and thorium-228 in UTS-1 and UTS-2.     

Determination of Lead-210, Radium-226, Thorium-228 and Uranium-238 in Five CCRMP Reference Samples by Gamma-Ray Spectrometry

Lead-210, radium-226, thorium-228 and uranium-238 concentrations have been determined in five CCRMP reference samples using direct gamma-ray spectrometry. Literature data are available for only lead-210 and radium-226 levels in these samples.     

New CCRMP Reference Uranium ore BL-5 And Sulphide Concentrates CCU-I, CPB-1 and CZN-1

Under the Canadian Certified Reference Mate-vials Project (CCRMP), four new ore reference materials, one uranium ore BL-5 and three sulphide concentrates (CCV-1, CPB-1 and CZN-1) have been recently issued. The preparation, characterization and certification of these samples are briefly presented.     

The Preparation of Marine Geological Certified Reference Materials - Polymetallic Nodule GSPN-1 and Marine Sediment GSMS-1 from the Central Pacific Ocean*

This report describes the location, collection, preparation, homogeneity testing, analysis, data-processing and assignment of certified values of a polymetallic nodule (GSPN-1) and marine sediment (GSMS-1). Materials used in the preparation of these reference materials were collected in 1986 and 1987 from the central Pacific Ocean, by the Chinese Ministry of Geology and Mineral Resources (MGMR). A total of fifty one recommended element concentrations and five proposed concentrations are reported for GSPN-1. For GSMS-1, a total of fifty recommended and seven proposed values are presented.     

厦门火烧屿裸露岩石的铀放射系不平衡

用HPGeγ谱方法测定了厦门火烧屿裸露岩石天然放射性核素^40K、^228Ra、^228Th、^238U、^226Ra和^210Pb含量，对其铀系不平衡关系进行了讨论，发现钍系核素^228Ra和^228Th基本上是平衡的，而大部分样品^226Ra相对于^228U、^210Pb相对于^226Ra亏损。由此推论，水体作用下岸边岩石中^226Ra直接进入水体，可以是海水中^226Ra的一个来源；岸边岩石中^222Rn逸出后，衰变^210Pb再进入水体，可以是海水中^210Pb的一个来源。     

Platinum-Group Element and Rhenium Concentrations in Low Abundance Reference Materials

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.     

中国的大洋多金属结核及沉积物标准物质系列

1986～1996年间我国研制了两批共６个海洋地质标准物质：3个多金属结核标准物质GSPN-1～3和3个深海沉积物标准物质GSMS-1～3,形成了两个标准物质系列。与美国、俄罗斯、印度和日本的同类标准物质相比,这些标准物质的主要特点是：①实用性强：这些样品主要取自世界上锰结核最富集、也是各国“先驱投资者”开辟区最集中的太平洋CC区;②系列性好：这些样品还可与美、俄的标准物质构成既具有较大的元素浓度范围又具有适当浓度梯度的标准系列;③被测定组分多（达79个）,定值组分达63个。其中包括58个组分的保证值和5个组分的参考值,全组分的加和均在99.5％～100.1％之间;④参加合作的国家数和实验室多:有18个国外实验室和包括台湾大学在内的14个国内实验室参加了合作分析。这就使这些标准物质具有较大的国际影响。     

PREPARATION OF THREE CHINESE CERTIFIED REFERENCE MATERIALS: PLASTIC CLAY, POTASSIUM FELDSPAR, SODA-LIME-SILICA GLASS

The preparation and homogeneity study of three certified reference materials, Plastic Clay GBW 03115, Potassium Feldspar GBW 03116 and Soda-Lime Silica Glass GBW 03117 are briefly presented. The recommended values with their uncertainties were assigned, after a cooperative study with 18 laboratories.     

Analysis of Sediments and Soils by X-Ray Fluorescence Spectrometry Using Matrix Corrections Based on Fundamental Parameters

Wavelength dispersive X-ray fluorescence spectrometry (WD-XRF) is widely used for the analysis of soils and sediments using well characterised procedures. However, difficulties can occur with samples such as unknowns containing small amounts of ore materials and samples collected from contaminated sites where trace elemental concentrations can exceed the concentration range for routine analysis. We studied the performance of a commercially available method, based on fundamental parameters (FP) to correct matrix effects. The spectrometer was originally calibrated with elemental or simple compound calibrants. Samples were analysed as pressed powder pellets. Eighteen sediment and soil reference materials, three of them with certified values for some of their constituents, were used to evaluate accuracy, by comparing results with recommended values and their standard deviations (RV ± 2s) or certified values and their confidence intervals (CV ± Cl). When results fell systematically outside these intervals, calibrations were refined with geochemical reference materials. The best agreement of results with recommended and certified values was obtained when the contents of H₂O and C in each sample were included as matrix constituents during calculations. The detection limits of trace elements tended to be relatively high, because the measuring conditions employed were not maximised for sensitivity. The main advantage of the method tested was that it enabled the analysis of samples with high concentrations of trace elements and the determination of elements such as F, Bi, Sb and W, which are not commonly included in quantitative XRF analysis of geological samples.     

Determination of the Platinum-Group Elements and Gold in Twenty Rock Reference Materials by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) after Pre-Concentration by Nickel Sulfide Fire Assay

The platinum-group elements (PGE) and gold have been determined in twenty international rock reference materials by inductively coupled plasma-mass spectrometry (ICP-MS) after pre-concentration by a nickel sulfide fire assay. It was possible to achieve determination limits for a 50 g sample that ranged from 1 pg g^-1 (Rh) to 23 pg g^-1 (Au). Compared to published certified and recommended values for rock reference materials, the trueness of the method was found to be good. However, in some cases we observed large deviations for all elements in the sub 10 ng g^-1 range within individual reference sample splits. Our results show that the PGE and Au are inhomogeneously distributed in the reference materials analysed here, where they are present in low concentrations, using 50 g test portions.     

Reference samples for use in analytical geochemistry: their availability, preparation, and appropriate use

A large number of certified and other reference samples are available for use in analytical geochemistry. Certified materials are preferred, but of much more limited availability than other reference samples for most geochemical applications. The availability of rock, sediment, soil, water, and plant reference samples is outlined; ore and mineral separate reference samples are not included in the discussion. The preparation of these materials, including the establishment of certified or recommended concentrations, is then reviewed. It is shown that comparable quality can be achieved for both certified and recommended concentrations, though it has not always been achieved in the past. Finally, the most appropriate ways to use reference samples in quality control and instrumental calibration are discussed.     

光石沟晶质铀矿:一种潜在的铀矿物电子探针定量分析标准样品

电子探针定量分析是采用元素A在待测样品中的特征X射线强度与标准样品中元素A特征X射线强度相比较而进行的,要实现未知样品的元素定量分析必须要具有相应的标准样品,目前可用于铀元素分析的电子探针分析标准样品极少,且缺乏与天然矿物成分、结构近似的标准样品。国际和国内已经制定了电子探针标准物质研制的规范(GB/T 4930—2008/ISO14595:2003),按该规范规定的方法研究了产于陕西光石沟铀矿床的晶质铀矿,结果表明:这些晶质铀矿晶形发育好,颗粒大,具备良好的纯度、均匀性和稳定性。随机选择30个颗粒进行均匀性检测,UO₂和PbO在95%的置信区间的平均浓度不确定度分别为0.275%和0.060%,具备非常好的均匀性;该晶质铀矿在电子探针电子束长时间(如360s)轰击下和在自然条件下存放,均具有良好的稳定性;采用五家实验室化学分析定值方法确定了该晶质铀矿的化学成分,并计算了不确定度,主量元素UO₂为(86.80±0.36)%,PbO为(4.80±0.07)%,其他元素也给出了参考值。综合以上研究结果:产于光石沟铀矿床的晶质铀矿满足GB/T 4930—2008关于电子探针定量分析标准样品的各项判据,是一个潜在的适用于铀矿物化学成分电子探针定量分析使用的天然矿物标准样品。     

珠江口沉积物210Pb分布特征及环境意义

根据珠江口及其邻近海域中的14个沉积柱样的210Pb随深度分布的测量数据以及210Pb过剩衰减法的原理,建立了基于傅立叶级数的变沉积速率模型,对珠江河口近50年来河口沉积物的沉积序列进行了分析。分别对各柱样的210Pb数据使用变沉积速率模型进行计算,获得了柱样更切实的沉积速率变化过程并分析沉积速率、年代计算结果与同时期内沉积环境之间的关系,结果表明:珠江口不同站位的沉积速率差异很大,几个站位的整体平均沉积速率分别是,7.25 cm/a,5.36 cm/a,3.26 cm/a,3.03 cm/a,1.58 cm/a;沉积速率的变化与同时期发生在区域内的洪水、风暴潮、人类活动、河口演变等一系列综合因素有较好的对应关系,这说明使用基于傅立叶级数的变沉积速率模型得到的210Pb沉积速率变化的垂直分布能够解释其对应时段内的沉积环境,此模型亦可为其它河口区域的210Pb沉积速率计算提供借鉴。     

Determination of Total Sulfur in Fifteen Geological Materials Using Inductively Coupled Plasma‐Optical Emission Spectrometry (ICP‐OES) and Combustion/Infrared Spectrometry

A method for the determination of total sulfur in geological materials by inductively coupled plasma‐optical emission spectrometry (ICP‐OES) is described. We show that good results were obtained using this method even for sample types with very low (< 20 μg g^?1) sulfur concentration (e.g., peridotite). Sulfur was determined in fifteen geological reference materials with different sulfur contents. For reference materials with certified sulfur contents, the ICP‐OES method gave results in excellent agreement with certified values, and uncertainties better than 4% RSD. ICP‐OES results for sulfur in other reference materials yielded RSDs better than 10%, where S concentrations were > 100 μg g^?1 (except for diabase W‐2a, 16% RSD). Reference materials with lower sulfur contents (< 40 μg g^?1) showed much higher RSDs (17–18%). Except for RMs with certified values for sulfur, most data obtained by the combustion infrared detection method generally showed higher concentrations than those measured by ICP‐OES and a better RSD (≤ 8% for all materials except DTS‐2b).     

Evaluation of lead isotopic methods for uranium exploration, Koongarra Area, Northern Territory, Australia

Analysis of radioactive (²¹⁰Pb) and stable lead isotopes in near-surface samples has been tested as a method of uranium exploration in the Pine Creek Geosyncline, Northern Territory, Australia. The lead isotopes were extracted from the samples by a mild leaching agent and were measured by alpha spectrometry for ²¹⁰Pb and by mass spectrometry for stable lead isotopes. The results are compared with those obtained by conventional methods utilizing measurements of radioactivity and radon (Track Etch) in situ and ²²⁶Ra, ²²⁸Ra and U contents of soils. The major problems addressed were whether the lead isotopic methods are more sensitive than the conventional methods and whether they can discriminate “real” anomalies from the common barren anomalies found in black soils and swamps which contain radium in excess of the uranium present.Four test areas, representing a range of exploration problems, were chosen in the vicinity of the Koongarra uranium deposits and 25 samples from each area were analyzed. Most samples have more ²²⁶Ra than uranium. Radium analyses of several water samples show the source of this radium to be non-uraniferous rocks within the Kombolgie sandstone. The results for soil ²²⁶Ra, radon, scintillometry and ²¹⁹Pb were generally closely correlated, and as a result, the ²¹⁰Pb method was not considered to have any advantages over the conventional methods.At the Koongarra X prospect, which has a weak surface expression, the ratio gave the strongest indication of the underlying uranium mineralization with an anomaly to background ratio of 12.5. However, this ratio is correlated with uranium content and does not offer any particular advantages over uranium analyses alone. More subtle indications of uranium mineralization were found by relating the radiogenic lead (²⁰⁶Pb) and the thorium-derived lead (²⁰⁸Pb) to the common lead content (²⁰⁴Pb). A plot of versus (horizontal axis) is linear for country rock samples, irrespective of the amount of more recently introduced ²²⁶Ra. Samples above uranium mineralization lie off this trend, along a line of near-zero slope. By the use of this plot, indications were found of the Koongarra No. 2 orebody, which is concealed by about 40 m of barren overburden; none of the other techniques detected this mineralization.     

Mass Fractions of Forty‐Six Major and Trace Elements,Including Rare Earth Elements,in Sediment and Soil Reference Materials Used in Environmental Studies

Development of new techniques, enabling simultaneous determination of large numbers of elements in environmental samples, can force analysts to use certified reference materials that do not contain all the elements of interest. In this paper, the mass fractions of forty‐six major and trace elements, including rare earth elements (REE), are presented in one soil (NCS DC 77302 also known as GBW 07410) and five sediment (Metranal‐1, IAEA 405, MESS‐3, NCS DC 73309 also known as GBW 07311 and NCS DC 75301 also known as GBW 07314) certified reference materials determined by high resolution inductively coupled plasma‐mass spectrometry. The selected certified materials represent a spectrum of geological matrices often analysed in environmental studies. Measured elements include certified elements, elements listed with information values as well as new elements absent from certificates, including REEs and some other elements. REE + Y mass fractions in the river sediment reference material Metranal‐1 are reported for the first time. The results obtained are in agreement with available certified or information values.     

The relationship of soil 210Po and 210Pb geochemical dispersion patterns to uranium mineralization

²¹⁰Po and ²¹⁰Pb measurements of soils delineated uranium anomalies at three out of four test sites in Ontario, Canada. Measurements were made of ²¹⁰Po in solutions produced by both complete digestion and partial leaching of soil samples. Direct plating of ²¹⁰Po onto metal plates was followed by measuring the alpha activity. Subsequent plating of ²¹⁰Po in-grown from ²¹⁰Pb in solution several months later confirmed the anomalies.The ²¹⁰Po and ²¹⁰Pb anomalies at three of the test sites coincided with ²²⁶Ra and ²²²Rn anomalies. Samples from the fourth uranium occurrence associated with a known ²²²Rn anomaly failed to show either a ²²⁶Ra anomaly on the one hand, or ²¹⁰Po or ²¹⁰Pb anomalies on the other. This suggests that the ²¹⁰Po and ²¹⁰Pb anomalies were probably produced by the decay of ²²⁶Ra contained within secondary dispersion haloes.Although anomalies due to the ²¹⁰Po and ²¹⁰Pb products of ²²²Rn have now been documented, prospecting methods based on their use as direct tracers of the migration paths of ²²²Rn require much further development.     

The relationship of soil Po and Pb geochemical dispersion patterns to uranium mineralization

²¹⁰Po and ²¹⁰Pb measurements of soils delineated uranium anomalies at three out of four test sites in Ontario, Canada. Measurements were made of ²¹⁰Po in solutions produced by both complete digestion and partial leaching of soil samples. Direct plating of ²¹⁰Po onto metal plates was followed by measuring the alpha activity. Subsequent plating of ²¹⁰Po in-grown from ²¹⁰Pb in solution several months later confirmed the anomalies.The ²¹⁰Po and ²¹⁰Pb anomalies at three of the test sites coincided with ²²⁶Ra and ²²²Rn anomalies. Samples from the fourth uranium occurrence associated with a known ²²²Rn anomaly failed to show either a ²²⁶Ra anomaly on the one hand, or ²¹⁰Po or ²¹⁰Pb anomalies on the other. This suggests that the ²¹⁰Po and ²¹⁰Pb anomalies were probably produced by the decay of ²²⁶Ra contained within secondary dispersion haloes.Although anomalies due to the ²¹⁰Po and ²¹⁰Pb products of ²²²Rn have now been documented, prospecting methods based on their use as direct tracers of the migration paths of ²²²Rn require much further development.     

密闭高温高压溶样ICP-MS测定56种国家地质标准物质中的36种痕量元素——对部分元素参考值修正和定值的探讨

标准物质参考值的准确性在测试仪器校准、分析数据质量监控以及方法评价等方面具有非常重要的作用.为了检验国家地质标准物质参考值的准确性,本文应用高温高压密闭溶样-电感耦合等离子体质谱法分析了国家地质标准物质的18种岩石(GBW 07103 ～ GBW 07125)、19种沉积物(GBW 07301 ～ GBW 07318)和19种土壤(GBW 07401 ～ GBW 07430)中36种痕量与稀土元素.结果表明,除个别标准样品中的几个元素(Ni、Cr、Pb、Co、Cu、Sc、Yb、Lu)外,其余国家标准物质中36种元素测定结果的相对标准偏差均小于10％;绝大部分元素测定值的相对误差小于10％,测定值与参考值能较好地吻合.将误差较大元素的测定值与其他实验室的测定值以及文献报道值进行了比较,指出已有的参考值需要修正;针对部分沉积物和土壤中的元素未提供参考值,如GBW 07306的Ni、GBW 07313的Be、Hf、Ta,GBW 07314的Li、Be,GBW 07409、GBW 07410和GBW0741 1的Hf、Ta,GBW 07426的Gd、Ta,本文给出了相应的参考值.