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排序方式: 共有115条查询结果,搜索用时 31 毫秒
51.
C. Corredeira M. F. Araújo A. Gouveia J.-M. Jouanneau 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(2):265-268
A geochemical study was carried out in sediment cores along the Galician Continental Shelf and at the mouth of the Vigo and
Pontevedra Rias. Multielemental analysis was performed by Instrumental Neutron Activation Analysis and Energy Dispersive X-ray
Fluorescence Spectrometry. Sedimentological and geochemical characterisation (lithogenic, biogenic and anthropogenic elements)
indicates different supplies for the fine-grained, deposited sediments. No significant heavy metal enrichment could be detected
in coastal sediments despite the current sediment contamination in adjacent Rias. Variations in the accumulation rates suggest
different factors controlling the sedimentation processes including sediment sources and geomorphology. 相似文献
52.
53.
Gold and silver in dross were determined by energy‐dispersive X‐ray fluorescence technique. Sample was prepared by pressed pellet method using microcrystalline cellulose powder as binder, and a method of standard additions was used for quantification. Lβ X‐ray of gold (11.4 keV) and Kβ X‐ray of silver (24.9 keV) were used for analysis. The measured concentrations of gold and silver were 132 ± 8 and 1181 ± 84 mg kg?1, respectively. The results were validated by instrumental neutron activation analysis technique. The t‐test indicated that there was no significant difference between results obtained by the two techniques. Energy‐dispersive X‐ray fluorescence is a simple, precise and accurate technique for the determination of gold and silver in dross. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
54.
Chemical characterization of selected metals by X-ray fluorescence method in particulate matter collected in the area of Krakow, Poland 总被引:1,自引:0,他引:1
L. Samek 《Microchemical Journal》2009,92(2):140-144
This study presents the results of year long (2007–2008) particulate matter collecting campaigns. The three particle size fractions of particulate matter were collected in Krakow, Poland. Fine fraction consists of particles of a diameter below 2.5 µm, medium is between 2.5 and 8 µm and coarse fraction contains particles above 8 µm. Elemental concentrations were evaluated for each sample. Following elements were measured by EDXRF method: K, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Br, and Pb. During each sampling campaign meteorological parameters such as temperature, wind speed, wind direction, humidity were taken from the same place. The highest values of mass particulate matter showed results from January 2008 and April 2008. These were about 14 µg/m3 for fine fraction, 8 µg/m3 for medium and 16 µg/m3 for coarse fraction. The lowest values were observed in May 2007, they were 4, 6, 6 µg/m3, respectively. During the winter season the wind speed was low and particulate matter remained in the air in high concentrations. In May 2007 the speed of wind was higher, reaching 2–3 m/s. PM was blown away from the city from the direction of N–W. Measured concentrations of elements were low, they were below permissible values specified by EU. The coarse fraction concentrations of Ca, Mn, and Fe were higher and characterized by the same trend. These samples were collected when the wind speed was low and its direction was from south-east. As concentrations of Cr, Cu, and Zn were low, these elements did not come from the south-east direction of Krakow. Concentration of Br correlates to the concentration of Pb. It suggests that they came from the same source (vehicles fuels burning). 相似文献
55.
The concentration of five different elements in six lichens species of different regions in Giresun and Ordu (Turkey) was determined using the energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied to the elemental analysis of lichens. An annular 50 mCi 241Am radioactive source and an annular 50 mCi 55Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li)detector which has a 147 eV full-width at half-maximum for 5.9 keV photons was used for intensity measurements. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, and barium. 相似文献
56.
Determination of metallic impurities in U3O8 using energy dispersive X-ray fluorescence spectrometry
V. Natarajan B.A. DhawaleB. Rajeswari N.S. HonS.K. Thulasidas N.K. PorwalS.V. Godbole V.K. Manchanda 《Spectrochimica Acta Part B: Atomic Spectroscopy》2008
In order to examine the capability of energy dispersive X-ray fluorescence spectrometry for the determination of some common metallic impurities in nuclear grade U3O8 matrix, a series of synthetic U3O8 standards, containing impurities such as Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni ,V, W and Zn in the concentration range, 100–1000 μg/g, were prepared. Using these standards, calibration curves were set up for different elements after optimizing the spectrometer parameters. Two synthetic samples and five reference standards obtained through an inter-laboratory comparison exercise within analytical laboratories of Department of Atomic Energy, India were analyzed to evaluate the performance of the newly developed analytical methods. The estimates for most of the analytes were in good agreement with the added amounts. The method is fast, since it requires no chemical treatment. The method has good precision for the analytes determined. 相似文献
57.
本文报道了应用X荧光光谱仪,ICP单道扫描光谱仪等检测方法开展无损检测,材料的表面薄层分析和快速半定量分析。这些工作弥补了PGS-2电弧的摄谱法的不足,提高了定性分析的质量和适用范围。 相似文献
58.
Certified reference materials (NIST 1645, BCR 143, IAEA 7, BCR 141, NIES_CRM_02, and IAEA 375) were used for determining the performance of a secondary target energy-dispersive X-ray fluorescence (EDXRF) spectrometer, Epsilon 5 (PANalytical, Almelo, the Netherlands). For the evaluation of the EDXRF spectra with polarized-beam high-energy excitation, the WinAxil software package has been applied. The results showed that Epsilon 5, EDXRF spectrometry is favorable for the determination of elemental concentrations in geological samples, but the sample preparation has the largest influence on the precision. However, they presented good agreement with certified values for most of the elements. 相似文献
59.
Tanil Akyüz Sevim Akyüz Ahmet Varinlioglu Abdullah Köse J. Eric D. Davies 《光谱学快报》2013,46(6):1131-1139
Abstract Nine ash samples collected from five coal fired power plants of Turkey have been analysed by FT-IR, EDXRF and γ -isotopic analyses methods. IR spectroscopy together with mineralogical analysis is found to be a useful method for investigating the inorganic chemical composition of the ashes which is an inherently variable material due to differences in the inorganic chemical composition of the source coal and in ash collection. Gamma-isotopic analysis indicated that all samples contained Ra-226, U-238 and Th-232. On the other hand Cs-137 (16.3 pCi/g) was found only in the ash sample collected from the Yata?an coal fired power plant. An ash sample taken from the electro-filter of the Ambarli, a fuel oil fired-power plant of Turkey, was also analysed for comparision and found that it contained least amount of U-238. 相似文献
60.
针对传统能量色散X荧光仪(energy dispersive X-ray fluorescence,EDXRF)分析土壤中微量重金属测量精确度低的问题,提出了一种X荧光仪改进方法。为了减少反射X射线的影响,入射X射线垂直照射样品,探测器平行放置与样品一侧且垂直于X射线。样品与探测器之间由准直器连接。对国家标样测量结果表明,仪器对Mo,Zn,Cu,Pb,Zr,Nb的检出限为0.4,6.68,1.97,6.84,1.60,7.59 mg·kg-1。各元素对数偏差在0~0.05之间。元素含量在三倍检出限以上RSD%(GBW)小于7,元素含量在三倍检出限内RSD%(GBW)小于15。为了验证改进后X荧光仪测量效果,在大兴安岭地区采集土壤样品与传统荧光仪进行比较分析。改进X荧光仪提高了土壤中微量重金属测量精度,满足野外地质普查要求。 相似文献