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1.
Mo and W have been determined in five CRPG and eight ANRT geochemical reference samples by spectrophotometric - zinc dithiol procedures. Although data are lacking for adequate comparisons on most samples, our data for tungsten in GIT-IWG MA-N and GIT-IWG BE-N are very near the presently proposed values.  相似文献   

2.
All data reported by 200 analysts (106 laboratories) are presented for the four ANRT samples: Diorite DR-N, Serpentine UB-N, Bauxite BX-N and Disthène DT-N. Recommended values are given for the major and minor elements. As far as the as trace elements are concerned, DR-N has been characterized for 35 elements whereas the other three samples have been for only 20 elements. Wherever possible, brief comments have been inserted so as to explain our way of assigning recommended or proposed values.
After more than a decade of existence the total number of data reported for all the four samples reach only 3200 units which are not sufficient enough for a valid evaluation of compiled data. It is also pointed out that these samples are most likely to be available even during the next century as they have been prepared in large quantities of the order of one ton. A plea is therefore made for contribution of more data particularly for trace elements and for major elements which are present as trace elements in UB-N, BX-N and DT-N.  相似文献   

3.
The concentrations of 25 trace elements have been determined in 15 international standard rock samples by isotope-dilution spark source mass spectrometry (ID-SSMS). This technique yields reliable data down to the ppb concentration range. The agreement between most of our data and recommended values is within 10%. However, for reference samples with low trace element contents (BIR-1, NIM-N, PCC-1, DTS-1), differences between our data and the literature can be as large as a factor of 80.  相似文献   

4.
Fifteen geochemical reference samples have been analysed for palladium using the stable isotope dilution technique. These include seven USGS, five CRPG and three CCRMP samples. Our results ape in reasonable agreement with the presently accepted values for the USGS samples, but are significantly lower than the present CCRMP values. Our data for the CRPG samples are the first to be published. This is the first reported study of the determination of palladium in silicate samples using the isctope dilution technique.  相似文献   

5.
随着实验技术的进步以及多接收电感耦合等离子体质谱仪(MC-ICP-MS)和热电离质谱仪(TIMS)的发展,近年来Ba 同位素的分析方法取得了显著进展。分析精度(δ138/134Ba,2SD)从之前的1 ‰ 提高到好于0.05 ‰。文章综述了近年来高精度Ba 同位素分析方法(溶液法)的发展历程,总结了国内外实验室关于不同类型样品的消解、Ba 元素化学纯化流程以及Ba 同位素质谱测定等方法,并对国内外多个实验室已发表的各类标准物质的Ba 同位素组成进行统计。研究结果可为Ba 同位素激光原位分析提供参考,为后续分馏机理解析和应用研究提供技术支撑。  相似文献   

6.
The reported values for the chromium contents of standard acidic rocks show a large spread, making it difficult to assign firm recommended values. A radiochemical neutron activation analysis procedure was developed and its reliability examined critically. The method involves separation of chromium as chromyl chloride by distillation followed by precipitation as barium chromate. The chromium content of a number of international standard rocks has been determined and results obtained are critically reviewed in relation to the available data.  相似文献   

7.
The preparation of two chromium ores as reference materials is described and the procedures used in the measurement of the homogeneity of the samples are outlined. Statistical analysis of the data submitted by 32 laboratories that resulted in the certification of the samples is presented. Certified values have been assigned for 11 constituents in the one sample and for 10 in the other sample. Provisional values have been assigned for FeO in both samples and CaO in one of the samples.  相似文献   

8.
The market for mineral water has been growing steadily over the last few years. Germany is the country with the highest number of bottled mineral water brands (908 bottled water samples from 502 wells/brands were analyzed). The per capita consumption of mineral water in Germany in 2003 was 129 L. A wide range of values of one to seven orders of magnitude was determined for 71 elements in the bottled water samples analyzed by ICP-QMS, ICP-AES, IC, titration, photometric, conductometric and potentiometric methods. A comparison of the element concentrations and the legal limits for both bottled and tap water (EU, Germany, US EPA, WHO) shows that only 70% of the 908 mineral water samples fulfill the German and EU drinking water (i.e., tap water) regulations for all parameters (not including pH) for which action levels are defined. Nearly 5% of the bottled water samples not fulfill the German and EU regulations for mineral and table water. Comparison of our results with the current German and European action levels for mineral and table water shows that only 42 of the bottled water samples exceed the limits for one or more of the following elements: arsenic, nitrate, nitrite, manganese, nickel and barium concentrations. Ten of the bottled water samples contain uranium concentrations above the 10 μg/L recommended limit.  相似文献   

9.
The uranium content of twelve rock reference samples, five from the Canada Centre for Mineral and Energy Technology, four from the Czechoslovakian Institute of Mineral Raw Materials and three from the United States Geological Survey was determined by neutron activation followed by delayed-neutron counting. Uranium contents measured ranged from 0.20 to 560 ppm. Three of the Canadian samples have relatively well established uranium contents. Of these we agree well with two of them; our value on the third is ∼13% lower than the recommended value. Comparison of our data on the other samples with other researchers is not yet possible because (i) no determinations are yet reported on several of these samples and (ii) even when several reported values are available, the wide disparity of those values does not allow meaningful comparison.  相似文献   

10.
Nine CRPG and ANRT reference samples have been analyzed for Hg by flameless atomic absorption spectrophotometry. Preliminary data are given but mercury homogeneity has not been tested. Results of determinations on USGS samples are reported and compared with available literature values.  相似文献   

11.
EDTA络合滴定法快速测定含钡铅矿石中的铅   总被引:1,自引:1,他引:0  
李志伟 《岩矿测试》2013,32(6):920-923
对于含钡铅矿石中铅的测定,采用EDTA容量法由于在分析流程中生成硫酸铅钡复盐使铅的分析结果偏低;采用钡铬酸铅容量法可以消除钡的干扰,但分析方法流程繁杂,耗时长。本文对现有的EDTA容量法进行改进,建立了一种快速测定含钡铅矿石样品中铅含量的分析方法。样品在盐酸体系中溶解,用硫酸沉淀分离可溶性钡离子,再用硫酸沉淀铅,所得的硫酸铅沉淀用pH=5.7的乙酸-乙酸钠缓冲溶液溶解,EDTA络合滴定法测定铅的含量。分析结果表明,盐酸用量为40 mL,50%硫酸用量为2滴时可以消除钡对铅测定的干扰,样品分解后硫酸铅沉淀20 min即可分离测定。本法的测定值与国家标准方法的测定值基本一致,方法精密度为0.1%~0.8%。方法中沉淀放置时间只有20 min,与国家标准方法和其他方法的沉淀放置时间(4 h或过夜)相比较,缩短了样品处理流程,满足了矿山企业选冶生产现场样品的快速检测要求。  相似文献   

12.
提出掺氧空气-乙炔火焰原子吸收光谱法测定地质样品中微量钡的新方法。使用磺基水杨酸作保护剂消除铝对钡的挥发原子化干扰,KCl作消电离剂消除钡的电离干扰。方法的检出限(K=3)为0.04mg/L。方法已应用于测定地质标准样品中的微量钡,结果与标准值相符,对GBW07103试样测定6次,RSD为5.4%。  相似文献   

13.
The five CRPG geochemical reference samples (BR, GA, GH, Mica-Fe and Mica-Mg) have been distributed as reference samples for more than twenty years. All data on trace elements in these samples available to the authors since their first reports have been compiled and evaluated. It has been possible to assign working values for more than forty elements in BR, GA, GH and Mica-Fe and for twenty-three elements in Mica-Mg. The samples are expected to last for another twenty years.  相似文献   

14.
The six ANRT rock reference samples (DR-N, UB-N, BX-N, DT-N, GS-N, FK-N) have been distributed as reference samples for nearly twenty years. All available data on trace elements in these samples are presented and evaluated. It has been possible to assign working values for nearly 40 trace elements. These samples prepared in 600 to 1300 kg quantities are expected to last for some decades to come.  相似文献   

15.
Since 1967–68, two mica reference samples, Biotite Mica-Fe and Phlogopite Mica-Mg, were made available to several geochemical laboratories. The analytical data reported during the past ten years by 142 geoanalysts belonging to 74 international laboratories are presented and assessed for deriving preferred values. Reaomrmended or proposed values are assigned for major, minor and several trace elements. The biotite Mica-Fe is better characterized for its chemical composition than the Phlogopite Mica-Mg. Both the samples are also proposed as geochronological standards. Because very few mica reference samples have been processed in large quantities, the international geochemiaal community is invited to contribute further useful data.  相似文献   

16.
We have used a new thermodynamic model of barium and calcium sulfate solubilities in multicomponent electrolyte solutions (Monnin, 1999) to investigate the stabilities of barite and anhydrite in seawater or in marine sediment porewaters at high temperature and pressure. As a further test supplementing those previously carried out during model development, we have calculated the temperature at which standard seawater becomes saturated with respect to anhydrite. The model predicts that, upon heating at 500 bars, standard seawater becomes saturated with respect to anhydrite at 147 ± 5°C, which compares well with the literature value of 150°C (Bishoff and Seyfried, 1978). At 20 bars the calculated saturation temperature is 117 ± 3°C. This points to a non negligible pressure effect even at moderate pressures.We have calculated the barite and anhydrite saturation indices for the in situ temperatures and pressures, from the composition of porewaters collected at ODP Sites 855, 856, 857, 858, 1035 and 1036 during ODP Legs 139 and 169 (Juan de Fuca and Gorda ridges, NE Pacific). Calculated saturation indices for porewater samples collected at depths corresponding to temperatures between 70° and 110-120°C at an in situ pressure of about 260 bars yield equilibrium values for anhydrite and barite. Saturation indices of samples collected at depths where the temperature exceeds 110-120°C, however, yield values indicating supersaturation with respect to anhydrite and undersaturation with respect to barite. This result is consistent with the redissolution of anhydrite during cooling, leading to the well documented sampling artifact affecting porewater compositions in high temperature marine sediments: anhydrite dissolution increases the porewater sulfate content, which in turn induces a loss of barium from solution through barite precipitation (the common ion effect). We postulate that this redissolution occurs in sediment samples for which the in situ temperature exceeds 110-120°C: below this limit anhydrite remains at equilibrium or does not have time to significantly dissolve before porewaters are sampled.  相似文献   

17.
The results of experimental studies on the macro- and microcomponent composition of the ion–salt complex of argillaceous siliceous rocks from the Bazhenov formation of West Siberia are presented. The studies were based on the analysis of samples using a high-resolution mass spectrometer with ionization in inductively coupled plasma, by the X-ray diffraction (XRD) method, and via the study of water and ammonium extracts from samples with a natural moisture content, as well as after drying. It was established that the composition of the solutions of water extracts from rocks with a natural moisture content belongs to the sulfate- sodium-bicarbonate type with increased content of dissolved silicic acid with weakly alkaline pH values (~9.5) and is considerably different from the content of water extracts from the samples after drying. Sodium dominates in the exchange complex; the cation exchange capacity is 14–19 mg-eq/100 g of rock. A sharp excess of the percentage abundance by 2–10 orders of magnitude was recorded for barium, boron, zinc, vanadium, uranium, and arsenic. The barium content in pore water exceeds the strontium content by a factor of 10, which is anomalous with respect to the reservoir formation waters in the majority of oil fields and to the ocean water.  相似文献   

18.
During the five-year period (April 1981 - March 1986), a series of fifteen rock reference samples, "Igneous rock series", has been prepared by the Geological Survey of Japan (GSJ). Based on the data available (published and communicated), consensus values for major, minor and trace elements have been derived; these values are presented for this second series of samples as well as for the first series of two samples, Granodiorite JG-1 and Basalt JB-1.  相似文献   

19.
The contamination of cuttings and side-wall core (SWC) samples in the Bambra-2 well by drilling-mud additives and natural hydrocarbons may cause Ruek-Eval Tmax (℃) data to be suspect, and affect its utility in the assessment of thermal maturity. The Rock-Eval results of 284 cuttings samples, 31 side-wall core samples and conventional core samples from the Jurassic-Cretaceous sedimentary sequences in the Bambra-2 well are presented in this paper. Significantly lower Tmax values from cuttings samples compared with Tmax values from conventional core samples and solvent extracted SWC samples, from the deeper and higher maturity interval, are thought to have been caused by contamination by diesel and other drilling-mud additives. The cuttings samples in the Barrow Group of Cretaceous may be contaminated by natural hydrocarbons, resulting their Tmax values to be 2-10℃ lower than a regularly increased Tmax trend from core samples. This study indicates that more reliable Rock-Eval Tmax data are obtained from the conventional core samples and solvent extracted SWC samples. This study also indicates that the Tmax values from some SWC samples were also affected by free hydrocarbons, due to the use of diesel as a mud additive as well.  相似文献   

20.
We used high-resolution spectra to compute model atmospheres to derive the atmospheric abundances of moderate barium stars. Comparing our results with analogous data for normal red giants, we find that the moderate barium stars appear to not differ systematically from normal red giants. Their chemical abundance anomalies show the same patterns and can be interpreted in terms of evolutionary effects: the evolutionary stage, mass, luminosity, and metallicity of the objects.  相似文献   

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