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1.
The high sensitivity of Secondary-Ion Mass Spectrometry (SIMS) in determining very low trace-element concentrations (down to few ppb wt) has been used to address the important issue of the Light-Lithophile Element (LLE) signatures of mantle peridotites and their potential utility as tracers of transfer of subducted material into the overlying mantle wedge operated either by slab-related fluids or melts. The effects of such metasomatic agents have been described and interpreted on the basis of geochemical and isotopic characteristics of peridotites. However, direct observation of metasomatic processes occurring in the mantle is limited because the most highly metasomatised peridotites are usually found as xenoliths which do not allow large-scale chemical information. In this context, the Finero phlogopite-peridotite massif (Ivrea-Verbano Zone, western Italian Alps) offers a unique opportunity because it contains hydrous mineral assemblages (amphibole + phlogopite ± apatite) and trace element enrichments, supposed to be related to the pervasive migration of slab-derived melts. In this study we report the results of texture-related SIMS investigations performed on a wide range of trace elements such as Li, B, Large-Ion Lithophile Elements (LILE), Rare Earth Elements (REE), Nb, Zr, Ti on clinopyroxenes from the Finero peridotite. SIMS analyses revealed unusual LLE signatures that highlight the role of crust-derived components and open new perspectives on the timing of metasomatic processes.  相似文献   

2.
Tea has been one of the most popular simulating beverages which is both heavily produced and consumed in Taiwan. The determination of minor or trace elements in drinking tea and tea leaves is therefore important for estimating the daily intake of Taiwanese considered as a safety indicator. In order to accurately and precisely determine the concentrations of trace elements in samples, several analytical methods such as AAS, NAA and ICP-AES are suggested. This paper attempts to utilize all three methods to determine the concentrations of minor or trace elements in different types of tea leaves and the extracts percolated from them. The influence of fermentation processes on the concentration levels of minor or trace elements in tea samples is investigated. Because only free metal ions are bioavailable for the human body, it is necessary to determine their concentrations in drinking tea. The dissolution of trace elements in drinking tea is therefore studied by simulating the common Chinese style of tea percolation. Concentrations of thirteen elements including Zn, Mn, Ca, Cu, Ni, Al, K, Mg, Cd, Pb, Na, Co and Sc are determined.  相似文献   

3.
微波消化-ICP-MS法测定尿样中15种金属元素   总被引:4,自引:0,他引:4  
采用微波消化-电感耦合等离子体质谱法测定尿样中的15种金属元素,方法回收率81%-107%,相对标准偏差为1.14%-6.71%,方法具有快速、简便、灵敏、准确的优点,对探索微量元素与健康的关系具有十分重要的意义。  相似文献   

4.
目的测定古造液酒中微量元素含量,并与饮用白酒、国囍酒比较,看其微量元素含量高低情况。方法采用电感耦合等离子体质谱法(ICP-MS)测定微量元素含量。检测限为0.30~3.43μg·L~(-1),回收率范围在95.4%~104.3%,相对标准偏差(RSD)范围在1.1%~2.0%。结果测定方法准确可靠。古造液酒中的微量元素明显高于饮用白酒和国囍酒。结论古造液酒富含微量元素,具有较高的临床价值。  相似文献   

5.
溪黄草微量元素含量及其溶出量分析   总被引:7,自引:1,他引:6  
用等离子体原子发射光谱法对溪黄草微量元素的含量进行了测定,溪黄草含有18种元素,其微量元素的水溶出量与溪黄草的提取方法有关。  相似文献   

6.
It is known that trace elements play an important role in a number of biological processes. These include the activation or inhibition of enzymatic reactions, competition between elements and metal proteins for binding positions and modifications in the permeability of cellular membranes. These elements may also influence carcinogenic processes, thus the knowledge of trace element concentrations in healthy and neoplastic tissues might help in diagnostic and in the etiology and development of cancer.  相似文献   

7.
Inflatable Gossamer’s structures which can be deployed in Earth orbit have great prospects in the future. Material for use in inflatable structures must be soft before and during unfolding and harden after unfolding. The best way for solidification of Gossamer’s structures is by chemical polymerisation of a composite material in space environment. The polymerisation processes of liquid polymer matrix in a free space environment are sensitive to microgravitation, temperature variations (−150 to +150 °C), high vacuum (10−3 to 10−7 Pa), atomic oxygen flux (in LEO), UV and VUV irradiations, X-ray and γ-irradiations, high energy electron and ion fluxes. In this paper experiments of the photopolymerisation processes under simulated free space conditions were carried out. The influences of high vacuum, temperature variations, high energy ion beam, radio-frequency and microwave plasma on polymerisation of UV-curing resin were observed. The effects of low molecular components evaporations, acceleration of curing kinetics, additional chemical reactions and mixing processes during polymerisation were observed. The photopolymerisation of inflatable structure was carried out under simulated temperature conditions of space flight in low Earth orbit. The results indicate a technology for large-size inflatable constructions in Earth orbit, in far space and on space bodies as for deployed antennas, solar sail stringers, solar shield stringers, frames for large-size space stations, frames for Moon, Mars, asteroids bases and frames for space plant on Earth orbit and other celestial bodies.  相似文献   

8.
A computer-controlled rapid-scanning echelle monochromator is used to determine the major, minor and trace elements in reference sediments and soils. The high resolving power of the echelle spectrometer effectively decreases line overlap interferences, and permits a wide selection of analytical lines to be used. The concentrations of 17 elements in five standard materials are determined by using a single set of analytical lines without any corrections for line overlap interferences. Averages of relative standard deviations and relative deviations from the certified values for the 17 elements range from 2.4 to 4.3% and from 1 to 5%, respectively.  相似文献   

9.
Higher concentrations of non-easily ionized elements (NEIE) increase the spectral line intensity of trace elements in the arc plasma. It was found that these additives do not greatly affect the evaporation processes of the trace elements. Changes in temperature, electron density and transport velocities together can optimize the excitation for particular atomic species. The importance of the investigations is to underline the possible application of NEIE in spectrochemical practice.  相似文献   

10.
采用微波消解技术,建立了一种电感耦合等离子体质谱法测定明胶空心胶囊中Cr,Co,Ni,Cu,Zn,As,Cd,Hg和Pb 9种微量重金属元素的方法。确定了微波消解仪和等离子体质谱仪的最佳操作参数,研究共存离子的干扰和消除方法,选择了各元素的测定同位素,以Ge,Rh和Tl为内标补偿基体效应,建立了样品测定方法。应用拟定的方法测定了不同生产厂家、不同批次的空心胶囊中微量重金属的含量。方法对试样中各元素测定的相对标准偏差为1.5%~14.1%,加标回收率在90.0%~102.0%。结果表明,方法简便、快速、灵敏,满足于空心胶囊中9种重金属元素的测定要求。  相似文献   

11.
Analytical methods were developed for the determination of trace elements in Antarctic krill samples applying inductively coupled plasma atomic emission spectrometry (ICP-AES) and graphite furnace atomic absorption spectrometry (GF-AAS). Cu, Fe, Mn and Zn were determined by ICP-AES, while Cd and Pb by GF-AAS technique. Two microwave assisted digestion procedures were elaborated for the preparation of 0.5-g krill samples using open and closed vessel systems. The efficiency of the digestion processes was checked by measurements of the total organic carbon content of the solutions obtained. The deviations of the analytical data from the certified values and the relative standard deviations of the concentration measurements were lower for all six elements investigated applying the closed vessel digestion system.  相似文献   

12.
四种中药的模糊聚类分析   总被引:1,自引:0,他引:1  
运用模糊聚类分析研究了药物常量、微量元素与疗效的相关性。结果表明,相关系数较大的药物,疗效相似,相关系数r=0.8时有两种药物聚类相似。提示药物中常量、微量元素含量与疗效密切相关,为新型药物的研制提供了科学依据。  相似文献   

13.
土壤、沉积物系列标准物质中38种元素的ICP-MS定值   总被引:14,自引:0,他引:14  
探讨了电感耦合等离子体质谱测定土壤元素的基体效应及元素间的基体干扰,采用模拟土壤元素天然组成比值的校正溶液,利用^115In-^103Rh双内标校正系统有效地抑制了分析信号的动态漂移,建立了测定土壤中元素的ICP-MS方法;对GBW07410-07416土壤、沉积物系列标准物质进行定值,测定结果与XRF分析结果比较,同时用于GBW07404、GBW07405、GBW07408、GBW07309管理样分析,结果令人满意。  相似文献   

14.
In natural waters trace elements, especially trace metals may be present in a variety of physicochemical forms. They may be associated with forms ranging from simple ions and molecules via hydrolysis products and colloids, pseudocolloids and organic or inorganic particles. The transition between categories is gradual. The presence of species differing in size, charge and density will influence on the transport, mobility and bioavailability of the trace element in question. Fractionation techniques which do not influence the distribution patterns are therefore required for speciation purposes. In the present work dialysis in situ and large membrane (hollow fibers) ultrafiltration are used for fractionation of low molecular weight species, colloids, pseudocolloids and particles. Due to the presence of foreign components transformation processes influence the distribution patterns of trace elements of interest. Sorption to foreign surfaces, complexation with agents present and aggregation of colloids (e.g., increasing ionic strength) result in a shift towards higher dimensions while desorption and dispersion processes mobilize the trace elements. Information on several components is therefore needed in speciation studies and a multielemental method of analysis having low determination limits must be applied. Instrumental neutron activation is appropriate to this kind of study because of its high sensitivity for simultaneous determination of a great-number of elements. Size fractionation techniques combined with INAA for the characterization of trace element species in natural waters will be discussed.  相似文献   

15.
概括了十余年来中医领域中运用微量元素先进测试方法对中医有关证、辨病辨证、舌象、辨证施治等方面作的大量研究,证实微量元素与它们之间有密切关系,既可作为中医有关诊断的客观指标,又可作为指导师辩证施治选 方用药的一个依据,但纵观全局,目前研究还不够深入,停留在表象推测为主动,无重大理论突破,需要中西医及理化多学科研究人员携手协同研究,以期获得新的成就。  相似文献   

16.
 Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used as a powerful multielement analytical method for trace analysis of geological glasses which are useful as reference materials for geochemical in-situ microanalytical work. The quantification of the analytical results was carried out using the BCR-2G and NIST 612 glass standard reference material (SRM). The experimentally determined relative sensitivity coefficients (RSC) for both SRMs vary between 0.2 and 3 for most of the elements, with increasing mass an increasing of relative sensitivity coefficients was observed. The relative standard deviation (RSD) for determination of trace element concentration of most elements (N=3) are between 2 and 10%. The determination of trace elements in various geological glasses by LA-ICP-MS yielded a good agreement with the reference values and those results of other trace analytical methods. Received October 15, 1999. Revision April 14, 2000.  相似文献   

17.
Trace elements such as Ag, Au, Bi, Co, Cu, Fe, In, Ni, Pb, Pd, and Sn can be preconcentrated from high-purity cadmium by partial dissolution of the matrix. The samples are coated by a thin film of mercury and dissolved in hydrobromic acid up to a small residue. In this residue the trace elements are enriched with recoveries of more than 95%. The elements are determined by AAS. For 10 g Cd the factor of enrichment is about 102, and the limits of detection are in the range of 0.1 ppm. The relative standard deviation was calculated to be about 5%. Reasons influencing the recovery of the trace elements are discussed.  相似文献   

18.
Silt and clay size fractions of soils, from a transect of six Spodosols formed in the Norra Storfjället Massif, were analyzed by neutron activation to determine the degree to which pedogenic processes have influenced the distribution of macro, micro and trace elements. The distributions of Mg, Ca and Fe, together with Co, Cr and other trace elements in the profiles, suggest the presence of different parent materials, with A and E horizons arising from an influx of aeolian sediment. Translocation processes, both physical and chemical, occurred in the soil concentrating Fe and Br in the spodic (Bs) horizons of the profiles. The rare earth elements (REEs) are predominantly associated with the heavy mineral fraction of the soil material. The distributions of chondrite normalized REEs patterns of the profiles indicate that light rare earth element (LREE) concentrations increase with horizon depth. The depletion of LREEs in the upper soil horizons confirms the presence of material that is chemically different from that in the lower horizons, thus indicating a distinct chemical difference from the local glacial deposits.  相似文献   

19.
C1-carbonaceous chondrites are known to have the highest meteoritic content of volatile elements. Nevertheless, most volatile elements, such as H, He, N and O, are excluded from the accordance with the solar photosphere. In meteoritic material, which condensed closer to the sun, even moderately volatile elements could not completely condense and their C1-normalized concentration ratios with refractory elements are typically depleted. In primitive terrestrial samples these ratios of (lithophile) moderately volatile to refractory elements are even lower. This suggests an accretion of our planet from material, which condensed closer to the sun than all available meteorites surviving in significantly farer distances in the asteroid belt. Evidence to that may come from agreements between most Earth-like meteorites with the depletion pattern of moderately volatile elements in the Earth’s mantle or rather related bulk data. Therefore, two samples from Hammadah al Hamra 073 and Sahara 0182, supposed to be further members of the most Earth-like Coolidge-Loongana grouplet, have been analysed by INAA. Together with two earlier analysed samples from the grouplet the results have been used in fingerprint studies with terrestrial data. In spite of internal spreading due to sampling of inhomogeneous material, the results are in accordance with a volatility-dependent model of depletion. Abundance ratios of Fe relative to Mn, Cr, and Si measured from the grouplet-abundances are depleted relative to calculated data from the total Earth, what can be explained with a 30 %-mantle-stripping from an impact of a Mars-sized body.  相似文献   

20.
FAAS法测定鸡血藤中的微量元素   总被引:2,自引:1,他引:1  
为研究金属元素在鸡血藤中的含量与药用功能采用标准曲线法,用空气-乙炔火焰原子吸收光谱法测定了鸡血藤中多种微量元素的含量。结果表明,方法的加标回收率在97.50%~99.60%范围内,RSD(n=6)在0.36%~0.57%之间。测定方法简单易行,方便快捷。  相似文献   

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