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.     

多种评价方法应用于天津核桃主产区的土壤环境质量评价

以天津市核桃主产区土壤和核桃为研究对象,分析了土壤重金属元素Cd、Hg、Pb、As、Cr、Zn和Cu的含量特征,选用内梅罗指数法、地累积指数法和污染负荷指数法等3种方法评价了土壤环境质量,并分析了核桃食用安全性.结果表明:研究区土壤样品中Cd、Hg、Pb、As、Cr、Zn和Cu的平均含量分别为0.19×10-6、0.0...     

发射光谱法测定岩石中十五个痕量稀土元素

岩石中稀土元素的配分可作为地壳、地幔演化的标志,尤其是元素Eu,就是地质时代和物质来源的指示剂。因此,岩石中痕量稀土元素的测定越来越引起地质工作者的关注。     

离子吸附型稀土监控样定值研究

离子吸附型稀土矿是中国极其重要、世界罕见的矿床类型,是中国的优势矿产资源。目前现有的稀土标样全部为稀土矿石成分分析标样,稀土元素以氧化物形式稳定存在,无法淋滤浸取,不能对离子吸附型稀土淋滤过程进行监控。为进一步满足离子吸附型稀土资源勘查和评价需要,本文按照导则《标准物质定值的通用原则及统计学原理》（JJF 1343—2012）,制备了三种岩性共9个离子吸附型稀土监控样。样品采自南岭地区典型富轻稀土（HREE）离子吸附型稀土风化壳,经干燥、球磨至200目后混合机混匀,以硫酸铵淋滤、电感耦合等离子体质谱法（ICP-MS）测试离子相稀土元素含量,检验样品均匀性,结果表明F值小于临界值F_{0.05（19,20）},样品均匀性良好。在两年内对样品进行4次稳定性检验,在95%置信度时│β₁│<t_0.05×s（β₁）,未发现明显不稳定变化,表明稳定性良好。由8家技术权威的实验室进行协作定值,经过统计计算给出各离子相稀土元素含量的加权平均值和扩展不确定度,定值结果涵盖除Sc以外的15种稀土元素。该系列监控样的研制能够为离子吸附型稀土矿产资源评价和有效利用等工作提供计量支撑。     

无机材料中24种组分X射线衍射物相定量分析外标法标准曲线库的建立

在Rigaku D／max-2200型X射线衍射仪定量分析软件的基础上，扩大并制作了外标法对无机材料中石英、刚玉、TiO2、BaTiO3等24种组分进行物相定量分析时的标准曲线，所制作标准曲线的相关系数为0．925～0．999。通过对已知含量样品和部分实际样品的测量，结果与实际值基本相符或和内标法的测量结果基本一致，说明建立的标准曲线可用于物相定量分析。     

Accurate Measurement of Lithium Isotopes in Eleven Carbonate Reference Materials by MC‐ICP‐MS with Soft Extraction Mode and 1012 Ω Resistor High‐Gain Faraday Amplifiers

Lithium isotopes in carbonate rocks and minerals can serve as important tools for assessing palaeoclimates and palaeoenvironments. However, carbonate bulk rock samples are commonly mixtures of carbonate and silicate minerals, which require the complete digestion of the carbonate without digesting the silicate. Additionally, the low Li content (ng g^?1 level) in carbonates provides an additional challenge. Hence, despite their wide applications, few carbonates have had their δ⁷Li values characterised, particularly carbonate reference materials, which hinders comparisons of Li isotope measurement results obtained in different laboratories and the further application of Li isotopes in geological studies. This study aimed to provide precise and accurate δ⁷Li values for carbonate reference materials based on an evaluation of sample leaching and the Li purification method for carbonates, as well as the adoption of soft extraction and 10¹² Ω amplifiers to increase the intensity/blank ratio and matrix effect on Li isotope measurement. The precision and accuracy of the proposed procedure were verified by analysing synthetic carbonate samples and mono‐elemental Li solutions. With the developed method we provide δ⁷Li values for eleven carbonate reference materials with a precision of ~ 0.4‰. The accuracy of the δ⁷Li values was validated using the standard addition method.     

GEOCHEMICAL STANDARD REFERENCE SAMPLES GSD 9–12, GSS 1–8 AND GSR 1–6

The 18 Chinese geochemical standard reference samples GSD 9-12 (stream sediments), GSS 1-8 (soils) and GSR 1-6 (rocks) were prepared after GSD 1-8 (stream sediments) for even wider and increasing needs of geology, exploration geochemistry and geochemical analysis. Usable values of 41 trace, minor and major elements of the 18 samples were published in 1984. In the following two years, efforts were concentrated on the determination of other elements, most of which are more difficult to determine accurately and hence not many data were available in the literature. At the same time, additional data on the 41 elements already evaluated were also submitted. In all, 155 234 results were available along with the 35 284 analytical data submitted. The processing of samples, the examination of sample homogeneity, the plan of collaborative analysis of the samples, and the criteria for defining the recommended values are described. The recommended or reference values of the 72 constituents, to-gether with the 35 284 analytical data of the 18 samples are published in this paper.     

The determination of chlorine in rocks and minerals by pyrohydrolytic method

In this paper a porcedute of pyrohydrolysis spectrophotometric determination has been established for chlorine in rocks and minerals. The selection of accelerator and its required quantity, the time and temperature of sample decomposition and the influence of interferring elements and other factors are also discussed in detail. Because samples are usually fused with alkalis, higher blank is an insurmountable problem. However, with our procedure, the above-mentioned drawback can be effectively overcome, and the determination of trace chlorine either in large or in minor quantities of samples also is rather ideal. The determined results indicate that the relative standard deviations are 8.7% in the former and 4.5% in the latter case. This procedure is simple, rapid and well reproduceable. The detection limit of the method is 10 ppm. The results obtained by our procedure are in good agreement with the proposed values from two reference samples in China (DZΣ-1 and DZΣ-2) and one international geochemical reference sample (RGM-1). This method has proved itself to be reliable.     

Traceability in Geochemical Analysis

A review is presented of "traceability" and the way this concept can be demonstrated in the analysis of geochemical samples. It is suggested that the two practical methods are (i) by the analysis of appropriate certified reference materials with an evaluation of the agreement between analysed and certified values, and (ii) by the appropriate use of definitive, reference and standard methods of analysis. The differences between these two methods of demonstrating traceability are considered and the difficulties in applying them are discussed.     

微波密闭消解-等离子体质谱法测定岩石样品中的稀土元素

建立了有微波密封ＨＦ＋ＨＮＯ３消解样品,等离子体质谱测定岩石样品中１５个稀土元素的分方法。用该方法对国内外岩石标准品进行测定,结果表明稀土元素的测定值与标准值之间的相对偏差小于５％,检出限为（０．１－０．９）＊１０＾－９,多次测定结果的相对标准偏差在１．３％－５．２％。各类实际岩石样品中稀土元素的分析结果均与地质规律相符,进一步证明了方法的可靠性。     

微波消解-电感耦合等离子体质谱法测定高岭土中10种微量元素

高岭土作为重要的铝硅酸盐,其微量元素的含量决定着高岭土产品的性能指标.高岭土的三种国家标准物质成分GBW03121、GBW03122、GBW03122a中均未含有As、Sb等10种微量元素的标准值,在高岭土的检测中只能采用近似的岩石标准物质作为监控物质,对高岭土组分的准确分析有一定影响.本文通过微波消解技术,对比了硝酸...     

Results for Fluorine in Coals and Other Reference Materials

Results of fluorine determinations by a pyrohydrolysis-ion selective electrode method are reported for four reference coals, two fly ashes and eight rock samples. These values were obtained during a study of Australian coals which showed that the standard oxygen bomb combustion method generally used for coals gives low results. The results are compared with available literature data for these reference samples which were obtained by a variety of methods.     

X射线能谱法测定土壤中7种主次量元素

采用粉末样品压片制样,土壤标准物质以及人工合成标样为标准,用Ｘ 射线荧光能谱仪对土壤试样中的Ｓｉ、Ｋ、Ｃａ 、Ｔｉ、Ｍｎ 、Ｆｅ 和Ｓｒ ７ 种主、次量元素进行测定。讨论了基体效应及校正等问题。方法经土壤标样分析验证,其结果与标准值符合较好,方法的精密度（ ＲＳＤ,ｎ ＝ ５） ＜ ３ ％ 。     

聚氨酯泡塑富集—石墨炉原子吸收分光光度法测定土壤样品中的痕量铊

本文论述了一种聚氨酯泡塑预富集—石墨炉原子吸收分光光度法测定土壤样品中痕量铊的方法。样品经盐酸—硝酸—高氯酸—氢氟酸分解后,再加入10％硝酸。在Fe件和过氧化氢介质中,痕量铊被聚氨酯泡塑富集。用蒸馏水在沸水浴中解脱,以抗坏血酸作基体改进剂消除基体影响后,用石墨炉原子吸收分光光度法测定痕量铊。方法检出限为0．2ng／g。用本方法测定土壤国家一级标准物质中痕量铊,结果与推荐值相符,12次检测结果的精密度（RSD）为：5．05％～8．74％。     

X射线能地测定土壤中7种主次量元素

采用粉末样品压片制样,土壤标准物质以及人工合成标样为标准,用Ｘ射线荧光能谱仪对土壤试样中的Ｓｉ、Ｋ、ｃａ、Ｔｉ、Ｍｎ、Ｆｅ、Ｓｒ７种、次量元素进行测定。讨论了基体疚及校正等问题。方法经土壤标样分析验证,其结果与标准值符合较好,方法的精密度《３％     

APPLICATION OF THE FIVE-MODE METHOD TO THREE GIT-IWG ROCK REFERENCE SAMPLES

The "Five-Mode Method" for evaluation of compiled data has been applied to three well-established GIT-IWG rock reference samples: Anorthosite AN-G, Basalt BE-N and Granite MA-N. Results are compared to the accepted values, and where the two values are not in accord, a new procedure, the Graphical Moving Mode, is introduced. It is used to provide a clearer picture of the nature of the distribution of the raw data for each constituent, and, possibly to demonstrate the advantages of using the modal approach.     

粉末压片制样-X射线荧光光谱法测定铁矿石中锌砷锰

应用X射线荧光光谱仪测定铁矿石中的锌、砷、锰含量,采用粉末压片法制样,并研究了制样的条件,确定了仪器最佳参数,建立了标准曲线。经国家实物标准铁矿石样品验证,测定值与标准值吻合,三元素的偏差均小于±0.007%;精密度试验表明相对标准偏差(n=10)均小于2.80%。大量实验数据表明,压片制样-X射线荧光光谱法测定锌、砷、锰元素的精密度高,准确可靠。该方法在检测准确度和分析速度上可以满足钢厂生产要求。     

泡沫塑料富集分离—石墨炉原子吸收法测定化探样品中的痕量金

样品用1＋1王水分解样品,在王水介质中,用泡沫塑料吸附金。在聚四氟乙烯塑料瓶中进行水浴加热溶解,以1%硫脲络合解脱金,在石墨炉原子吸收分光光度计上,采用自动进样方式测定金。经国家一级分析标准样品验证,结果与标准值相符。     

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。