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1.
Instrumental neutron activation in geoanalysis 总被引：1，自引：0，他引：1
Theoretical aspects of instrumental neutron activation analysis (INAA) are discussed. Various applications of INAA to exploration geochemistry are described demonstrating its capabilities and its limitations.Cost, turnaround time, high sensitivity for certain elements, the non-destructive nature of analysis and its precision and accuracy have combined to make INAA an indispensible method for multielement determination on virtually all geological matrices. Humus, vegetation, heavy minerals, lake bottom sediments as well as rocks and soils comprise the major sample types analyzed by INAA. As many as 50 elements can be determined routinely and easily by INAA. 相似文献
2.
Zdenek Randa Jaroslav Frána Jirí Mizera Jan Kucera Jirí K. Novák Jaromír Ulrych Anatolij G. Belov Oleg D. Maslov 《Geostandards and Geoanalytical Research》2007,31(3):275-283
More than 130 samples of Tertiary phonolitic, trachytic and trachyandesitic rocks, representing evolved members of strongly and weakly alkaline volcanic rock series of the Ohre (Eger) Rift in the Bohemian Massif, Czech Republic, were analysed by instrumental neutron and photon activation analysis (INAA and IPAA, respectively). Forty-two major and trace elements were determined to explain the origin of such evolved rocks. Specific features of INAA and IPAA of the silicic, highly alkaline rocks are discussed, and results for selected samples are given. 相似文献
3.
Results of measurements of twenty-seven elements, most of them in trace amounts, by Instrumental Neutron Activation Analysis (INAA) in twenty-nine international geochemical reference samples from Canada, U.S.A., Japan, France and South Africa, are reported and compared with available literature values. In general, our data agree well with literature values. The disagreement of our results (e.g., Zr in Canadian syenites and several trace elements in USGS ultrabasic rocks) with those reported by other workers is briefly discussed and ways of improving INAA are pointed out. The present report includes data on several trace elements for which existing data are rather scarce. 相似文献
4.
Eric L. Hoffman 《Journal of Geochemical Exploration》1989,32(1-3)
Various methods are described for the analysis of Au and the Pt-group elements (PGE) using different geochemical media commonly collected by the exploration geochemist. The methods described utilize primarily the Instrumental Neutron Activation Analytical technique (INAA) in use at a commercial INAA laboratory.Rocks and soils are routinely analyzed by using a Pb fire-assay preconcentration on a 20-g sample and then analyzing the resultant Ag dore bead by INAA to a detection limit of 1 ppb. Growing rapidly in popularity is the analysis of a 30-g aliquot of sample for 34 elements including Au, solely by INAA. The elements included provide a wealth of information of a geological nature.Due to the very inhomogeneous nature of Au occurring in heavy-mineral concentrates it is imperative to analyze the whole concentrate. The only method which can provide a multielement analysis and still retain the sample intact is INAA.Biogeochemistry using either humus or vegetation as the sample media is rapidly becoming widely used. INAA provides a very sensitive means of determining Au and 34 other elements rapidly and at relatively low cost.These and other methods using the INAA technique for Au and the Pt-group will be described. 相似文献
5.
The purpose of this study is to investigate the enrichment level and dispersion patterns of Se and associated elements in rocks, soils and crops which were collected in the Dukpyung and the Chubu areas covered with black shales of the Okchon Group in Korea. Rock and soil samples were analyzed for Se including multiple elements by ICP, ICP-MS and INAA, and crop samples by INAA. Soil pH and loss-on-ignition (LOI) were also measured. 相似文献
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M.D. Norman W.P. Leeman D.P. Blanchard§ J. G. Fitton† D. James† 《Geostandards and Geoanalytical Research》1989,13(2):283-290
Element concentration data for a set of silicate igneous rocks have been determined by four independent analytical methods: inductivelycoupled plasma emission spectroscopy (ICP), instrumental neutron activation analysis (INAA), x-ray fluorescence (XRF), and isotope dilution mass spectrometry (ID). The results show excellent agreement among elements determined by more than one technique, and demonstrate the suitability of commercially available ICP instrumentation for the routine analysis of geologic material compared to other standard methods. 相似文献
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L. Paul Bédard 《Geostandards and Geoanalytical Research》2008,32(4):399-403
These mature analytical techniques do not show any change in publication level from the previous two years and AAS remains dominant in terms of the number of publications. The last two years have seen fewer technical improvements than in the previous review period. Some interesting papers dealing with uncertainty and quality assurance in INAA were published during 2006–2007. It is suggested that photon activation should be reconsidered because the source of electron accelerators has recently improved. A technique to preconcentrate Se for INAA determination has also been proposed. In the case of AAS, papers on analyte preconcentration continue to be more abundant than those relating to instrumental modification. Sample preparation for AAS is also active and ultrasound‐assisted leaching shows some promising applications. There were an unusual number of reviews concerned with AAS and those important to geological samples are cited here. A technique to preconcentrate Cr in water is presented and a new device to determine As and Se is showing some potential uses. Confocal X‐ray mapping continues to show interesting developments. One group developed a technique to perform XRF inside an oyster and an interesting application of μ‐XRF mapping of sediments is presented. Determination of platinum‐group elements (at μg g1 concentrations) can be carried out very quickly with an improved XRF technique. 相似文献
10.
中国火成岩化学元素的丰度与分布 总被引：19，自引：3，他引：19
在中国各构造单元构选采了１０３６４件火成岩样品合成１１３１个分析样，采用仪器中子活化法，Ｘ射线荧光光谱法，原子吸收法，原子荧光光谱法，催化波极谱法和分光光度法等１５种可靠分析方法进行测试，对一些难测痕量元素采用了最新的分析研究成果，以同类国家一级标准物质监控分析质量。 相似文献
11.
潘集煤矿二叠纪主采煤层中微量元素亲和性研究 总被引：5，自引：0，他引：5
安徽淮南煤田位于华北地台南端 ,发育了华北地区二叠纪含煤岩系中层位最高的可采煤层。采用仪器中子活化分析法 (INAA)测试了淮南煤田潘集煤矿二叠纪主采煤层 13个样品的 36个微量元素的浓度分布 ,并对其共生组合特点、地球化学特征及稀土元素配比模式作了初步分析 ,结果表明 ,煤中不同微量元素显示出不同的亲和性质。元素Br,As ,Sb ,Ni和Co等趋于在煤中富集 ,其中Br的有机亲和性最大。元素Na ,K ,Rb ,Th ,Hf,Zr ,Ta和REE则在煤层与顶底板接触带的碳质泥岩中富集 ,表现出与细粒陆源碎屑物更强的亲和性。其它元素倾向性不甚明显 ,但Fe ,Ca ,Sr ,HREE等元素在海水影响强度增大的煤层中含量增加。元素As,Cs,Ni,Fe和Ca在煤层中含量变化较大 ,其变异系数大于 1,其它元素则相对稳定 ,表明同一矿区煤层中微量元素含量在不受其它地质作用明显叠加影响时具有一定的稳定性。本区煤层稀土元素配比模式与华北其它地区C—P纪煤基本类似 ,普遍存在Eu亏损现象。 ∑REE在煤中分布范围为30× 10 -6～ 95× 10 -6,在顶板泥岩中超过 2 0 0× 10 -6。煤层中部 ∑REE降低 ,HREE相对富集。聚类分析表明 ,元素As ,Se ,Ag和Fe关系密切 ,这与煤中黄铁矿等成岩矿物有直接关系 ,泥炭沼泽演化期间或之后海水的直接或间接影响会促使这 相似文献
12.
采用化学法和中子活化(INAA)法对采自山西阳泉三矿山西组3号煤层和太原组12号煤层的3件煤层夹矸粘土岩样品的8种常量元素(氧化物)和33种微量元素含量进行了测定。通过对具有示踪意义的元素及其比值的对比分析,3个样品总体上均不具有典型的沉积岩特征,应该是由酸性或酸性偏碱性火山物质(降落的或陆源搬运的)在地表覆水较浅的弱氧化条件下经原地淋滤、蚀变形成的。原岩蚀变程度较高,不稳定或较不稳定的元素大量流失,甚至一些较稳定的元素(如高岭岩中的铁、锰)也明显流失。强烈的化学蚀变以及岩石中矿物成分的变化是造成粘土岩间以及粘土岩与原岩间元素(尤其是REE)含量及REE配分模式差异的主要原因。 相似文献
13.
Yu-Jun Zhang Xing-Bin Li Lin-Shan Song Ling Yuan Bao-Guan Chen Bing-Ru Chen Yu-Oi Wang Jing-Xin Sun 《Geostandards and Geoanalytical Research》1986,10(1):61-71
The concentrations of 36 elements in geochemical reference samples issued by the Ministry of Geology and Mineral Resources of China were determined by neutron activation analysis. Three main variants of the technique, instrumental, epithermal, and nreirradiation separation neutron activation analysis (INAA, ENAA, PNAA), were employed in a systematic study of the samples by three laboratories: the Institute of Atomic Energy of the Academia Sinica (INAA, ENAA), the Institute of High Energy Physics of the Academia Sinica (INAA), and the Institute of Geophysical and Geochemical Prosnecting of the Ministry of Geology and Mineral resources (INAA,PNAA). Both long and short irradiations and both Ge(Li) and HPGe detectors were used. A supplementary software nackage for data processing was developed. About 81% of the data determined by neutron activation agreed with recomended values with in 15%. 相似文献
14.
During 1975–1977, the USGS reference rocks GSP-1, BCR-1 and from 1977 onwards AGV-1 have been systematically analysed in routine INAA as test samples. The results are given for up to 26 elements per sample and the reliability of our setup is demonstrated. For further 17 geochemical reference samples, new results are presented and compared with available data. 相似文献
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A SELF-CONSISTENT COMPILATION OF ELEMENTAL CONCENTRATION DATA FOR 93 GEOCHEMICAL REFERENCE SAMPLES 总被引：5，自引：0，他引：5
Randy L. KOROTEV 《Geostandards and Geoanalytical Research》1996,20(2):217-245
Concentration data obtained by instrumental neutron activation analysis (INAA) are presented for up to 36 chemical elements in 93 geochemical reference samples, including some for which there are little previous data. Because all data are based on at least three independent analyses, and for many of the data the uncertainty associated with counting is an insignificant source of error, the values presented here are considered of higher precision than generally reported by INAA. Information on subsampling error (sample heterogeneity) is also presented. 相似文献
17.
通过对秭归地区闪长岩岩体风化壳中微量元素的分布规律研究,将该风化剖面中的微量元素划分为3类。第一类包括Sc、V、Cr、Co、Ni、Cu、Zn、Zr、Hf、Nb、Ta、U、Th、Mo、W,基本属于非活动性元素,在风化过程中得以有效保留,其中U、Cr、Cu等受氧化还原条件的影响,有时呈局部富集现象,规律性不明显。第二类以Ca、Rb、Cs、Sr、Ba、Pb、Ga、Gd、Tl为代表,随着风化作用的进行而逐步从风化壳中淋失,属活动性元素。第三类以稀土元素为代表,在风化壳内部发生局部的再分配,从剖面上层随风化溶液向下淋滤亏损,到剖面中下部沉淀富集,其中重稀土元素的淋失程度大于轻稀土元素。由于母岩中斜长石的风化淋滤,Eu在氧化环境下逐渐从正异常变为负异常。Ce在地表氧化条件下很容易生成四价氧化物（方铈石）,并在表层明显富集,剖面介质中氧化还原条件的变化导致Ce的波动变化。 相似文献
18.
The abundances of 24 major, minor and trace elements have been measured by INAA in Luna 20 metaigneous rocks 22006,1 and 22007,1, breccia 22004 and soil 22001,9 and in Apollo 16 soils 62281, 66041 and 66081. An additional 12 trace meteoritic and non-meteoritic elements have also been determined in 22001 and 62281 soils by RNAA. The bulk compositions of L 20 and Ap 16 rocks and soils show close similarity between the two highland sites. There are appreciable differences in bulk compositions between the L 20 highland and the L 16 mare site (120 km apart), suggesting little intermixing of rocks and soils from either site. Luna 20 rocks 22006 and 22007 are nearly identical in chemical composition to Ap 16 metaigneous rocks 61156 and 66095. Luna 20 rocks are feldspathic and are similar to low K-type Fra Mauro basalts. Such rocks and anorthositic gabbros appear to be the major components in highland soils. Luna 20 soil can be distinguished from Ap 16 soils by lower abundances of Al2O3, CaO and large ion lithophilic elements. Luna 20 breccia 22004 probably is compacted soil. All L 20 samples show negative Eu anomalies with ratios of 5.8, 7.2, 3.9 and 3.3 for rocks 22006, 22007, breccia 22004 and soil 22001, respectively. Norite-KREEP is insignificant, ≤1 per cent, at the L 20 highland site. The derivation of the L 20 soil may be explained by ≈33 per cent of L 20 metaigneous rocks and ≈ 65 per cent anorthositic gabbroic breccia rocks like 15418 (with a positive Eu anomaly) and ≈ 2 per cent meteoritic contributions. Interelement correlations observed previously for maria are also found in highland samples. Luna 20 and Ap 16 soils are low in alkalis. Both soils show an apparent Cd-Zn rich component similar to that observed at the mare sites and high 11 abundances relative to mare sites. The Ap 16 (62281) soil contains a fractionated meteoritic component (probably ancient) of ≈ 1.5 per cent in addition to ≈ 1.9 per cent Cl like material. Luna 20 soil may simply contain 1.9 per cent Cl equivalent. 相似文献
19.
ZHU Xiaoqing 《中国地球化学学报》2005,24(4):306-315
Experimental studies were undertaken on leaching of sedimentary rocks （ dolomite and sandstone） and Hg, Sb ores by distilled water under the condition of a completely open system （room temperature and room pressure）. The aim is to find whether the halogen elements or metal elements first enter the solution at the early stage of meteoric waters converting to groundwaters and ore fluids, and, at the same time, to understand how and when they enter distilled water solutions from the rocks. The experimental resuhs have shown that F and Cl began to enter the fluids in the initial period of thirty days. With increasing leaching duration, the amounts of the elements that entered the fluids increased steadily. During the period from 120 days to 150 days the amounts increased more drastically, followed a slow increase. It is found that the capability of Cl entering the solutions is much greater than that of F. Hg and Sb were found not to have entered the solutions till 120 days later. During this period of time the pH value of the solutions began to drop. As for Hg and Sb ores, Hg and Sb began to enter the solutions on the 60th or 90th day, greatly ahead of schedule, but the two metallic elements in the rock samples began to enter the solutions 150 days later. Relatively speaking, Hg is more easily leached out than Sb from the rocks. In some rock samples, Sb could be detected in the solutions at the end of the experiment. However, Cu, Pb and Zn had not been detected in the leaching solutions from the beginning to the end of the experiment. In the whole leaching process the pH value of the solutions tend to decrease slowly from 7.1 at the beginning to 6.5 at the end. That is to say, in the interaction between pure water and rock the halogen elements in the rocks were preferentially leached out and then entered the fluids. With increasing water/rock reaction duration and amount of halogen-group elements in the solution and with decreasing pH value of the solution, some active metallic elements began to release in small amounts. This experimental result can explain the source and mechanism of volatile components and trace metals in underground waters. Meanwhile, as for those ore deposits produced by ore fluids derived from meteoric waters, the experimental result is also helpful to the understanding of the geochemical variation trend at the initial stage of conversion of meteoric waters to ore fluids. 相似文献
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中国PGE矿床类型分析 总被引：22，自引：6，他引：16
中国PGE（铂族元素）矿床类型分析,PGE（铂族元素）矿床包括Pt,Pd,Rh,Ru,Os,Ir6种元素,它们有着很强的亲“S”性和亲“Fe”族元素性,同时和Mo,Te,As,Sb,Bi等元素也有亲缘关系。这些相关元素在不同介质中,组成不同的元素组合,叫做元素“序列”,共有7个序列,它们对PGE形成有选择性的萃取和捕获能力,叫“萃捕剂”,再加上PGE自身的地球化学差异性,就可能形成多种不同的PGE矿床类型。列举了6个矿床实例,提出了成矿五要素,分析了中国PGE矿床前景,认为成矿和地幔岩初始岩浆密切相关。 相似文献