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1.
The low detection limits and multi‐element capability of inductively coupled plasma‐mass spectrometry (ICP‐MS) makes it an attractive option in a wide range of environmental, medical, biological, industrial and archaeological applications. Quadrupole ICP‐MS is used to determine element concentrations in a diverse range of sample types, often very different from the geological applications for which ICP‐MS was originally developed. Whilst modern instruments are robust and capable of a high degree of automation, it is essential that users of both instrumentation and data are aware of the strengths and limitations of the technique. Many people who are now involved with the operation and application of ICP‐MS instruments are not specialists in the field, as was usually the case amongst early operators. This back‐to‐basics review is aimed at the novice user and includes a guide to ICP‐MS instrumentation and performance. Whilst solids, liquids and gases can all be measured by ICP‐MS, discussion of sample introduction is limited to liquids. Requirements for producing good quality data, including aspects of sample preparation, calibration, and methods of interference limitation are also discussed.  相似文献   

2.
New sample preparation and ion-exchange separation methods as well as instrumental measurement protocols were established for the determination of trace-level Cd, In, and Te concentrations in geological materials by isotope-dilution mass spectrometry. High precision isotope ratio measurements were performed with a multiple collector inductively coupled plasma-mass spectrometer (MC-ICP-MS). The mass biases incurred for In and Te were corrected by adding and monitoring Pd and Sb standard solutions, respectively. Mass fractionation of Cd was corrected by using the mass fractionation factor calculated from the measurement of a standard solution. The measurement precision was better than 1 % for Cd, In and Te. Detection limits were < 1 ng g-1 for Cd, < 0.02 ng g-1 for In and Te. Using these new analytical techniques, the concentrations of Cd, In and Te were determined in six international geological reference materials. Concentrations could be reproduced within 3% for Cd, 4% for In and 10% for Te. Sample heterogeneity and volatility problems might have been the reason for the relatively large differences between Te replicates. Our results displayed excellent reproducibility compared with those of other techniques and agree well with data from previously published recommended values.  相似文献   

3.
人工神经网络与分析测试技术的研究与发展   总被引:8,自引:0,他引:8  
罗立强  马光祖 《岩矿测试》1997,16(4):267-276
回顾了人工神经网络研究的发展历程,简要介绍了神经网络模型与算法,对分析测试技术和相关学科中的人工神经网络研究及在流程控制、错误诊断、参数估计、传感器模型、模式识别与分类、环境监测与治理及光谱与化学分析中的应用等作了评述。引用参考文献113篇。  相似文献   

4.
Recent developments from 2008 to 2009 in ICP-MS engineering, methods and applications are reviewed here. Of particular emphasis are advances in: (a) maximising sensitivity and reducing elemental/isotopic fractionation during laser ablation processing; (b) developing new analytical techniques to measure major, minor and trace element abundances without depending on matrix-matched calibrating materials, pre-determined internal standard concentrations and/or multiple analytical methods; (c) applying in situ and solution-based ICP-MS techniques to the analysis of forensic materials for criminal and/or nuclear investigations; and (d) improving precision and limits of detection of laser ablation multi-collector ICP-MS measurements of (ultra) trace elemental and isotopic abundances.  相似文献   

5.
多接收电感耦合等离子体质谱仪以及色谱分离和纯化方法的应用,大大提高了碲(Te)同位素的分析精度和效率,推动了碲同位素研究。本文综述了Te同位素研究的最新进展及其地质应用。碲具有亲硫和亲氧双重属性,同时具有一定的挥发性。自然界(包括陨石)中碲同位素(δ130/125 Te)的变化范围为-4.12‰~2.15‰。其同位素分馏受到不同过程的控制,其中球粒陨石碲同位素分馏主要受陨石形成过程中碲的蒸发和冷凝过程的控制,该过程中可引起高达6.9‰的分馏;自然界中氧化还原反应也可以引起较大的碲同位素分馏(4‰),因此碲同位素可能成为反应成岩成矿过程中氧化-还原条件变化的指标;此外,有机溶剂(如石油)参与的萃取作用可引起1.8‰的碲同位素分馏效应,这一效应在重稳定同位素研究过程中需要引起足够的重视。随着碲同位素分馏机制的进一步明晰,碲可能在示踪成矿物质来源、限定成矿时间以及指导矿产勘查等方面得到更为广泛的应用。  相似文献   

6.
Tower platforms, with instrumentation at six levels above the surface to a height of 30 m, were used to record various atmospheric parameters in the surface layer. Sensors for measuring both mean and fluctuating quantities were used, with the majority of them indigenously built. Soil temperature sensors up to a depth of 30 cm from the surface were among the variables connected to the mean data logger. A PC-based data acquisition system built at the Centre for Atmospheric Sciences, IISc, was used to acquire the data from fast response sensors. This paper reports the various components of a typical MONTBLEX tower observatory and describes the actual experiments carried out in the surface layer at four sites over the monsoon trough region as a part of the MONTBLEX programme. It also describes and discusses several checks made on randomly selected tower data sets acquired during the experiment. Checks made include visual inspection of time traces from various sensors, comparative plots of sensors measuring the same variable, wind and temperature profile plots, calculation of roughness lengths, statistical and stability parameters, diurnal variation of stability parameters, and plots of probability density and energy spectrum for the different sensors. Results from these checks are found to be very encouraging and reveal the potential for further detailed analysis to understand more about surface layer characteristics.  相似文献   

7.
This review describes significant developments in trace element determination using inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS) that were reported in 2004 and 2005. It focuses on the application of ICP techniques to geological and environmental samples; fundamental studies in ICP-MS and ICP-AES instrumentation are not included. The literature reviewed indicated that the majority of new publications concerned advances in ICP-MS analysis rather than ICP-AES. However, ICP-AES developments are still being published, particularly in the areas of sample preconcentration and sample introduction. The trend in increasing publication of developments in hyphenated speciation techniques looks set to persist as knowledge of elemental speciation becomes critical for many environmental studies. Collision or reactions cells were the most reported technique for spectral interference removal in ICP-MS, probably reflecting the growing adoption of cell instruments in laboratories during the last few years.  相似文献   

8.
9.
Laser ablation ICP-MS has been used to produce element profiles from polished coal samples. The elements analysed (V, Ge, Ni, Cu, Zn, Sr and Ba) were those known to have an organic association, with the addition of Al and Fe as controls on the clay and pyrite abundances. The element profiles were compared with the petrography and a statistical analysis was also carried out. Sporinite was found to have low trace element concentrations, inertinite higher concentrations of detrital elements and vitrinite higher concentrations of V, Ge and Al. The relationships between these elements are explored and all are thought to be present in the organic matter and not as minerals. It is thought that these elements became concentrated during diagenesis, with the possibility that some of the Al could be residual. The Cu/Ni ratio in the pyrite is relatively constant, suggesting constant ionic proportions during diagenesis, and possibly a seawater source.  相似文献   

10.
This review describes recent developments in trace element analysis using inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). It aims to focus on the application of ICP techniques to geological and environmental samples. Therefore, fundamental studies in ICP-MS and ICP-AES instrumentation have largely been ignored. Whereas the majority of literature reviewed related to ICP-MS, indicating that ICP-MS is now the preferred technique for all geological analysis, there is still a steady development of ICP-AES to environmental applications. It is clear that true flexibility in elemental analysis can only be achieved by combining the advantages of both ICP-AES and ICP-MS. Two particular groups of elements (long-lived radionuclide and the platinum-group elements) stood out as warranting dedicated sections describing analytical developments these areas.  相似文献   

11.
12.
We report new data on the trace element concentrations of Mg, Cr, Mn, Co, Ni, Cu, Zn, Sr, Cd, Ba, La, Ce, Nd, Pb and U in USGS carbonate reference materials (MACS-1 and MACS-2) and compare solution ICP-MS and LA-ICP-MS trace element determinations on landfill calcites using calibration to different reference materials (MACS-1 and MACS-2 carbonate and NIST SRM 612 glass). Very good agreement (differences below 10% relative) was found between laser ablation and solution ICP-MS data for MACS-1 with higher concentrations of trace elements (values between 100 and 150 μg g−1), with the exception of Cu and Zn. Similarly good agreement was found for MACS-2 with lower trace element concentrations (units to tens of μg g−1), with the exception of Cr, Co and Zn. The MACS-1 reference material for calibration of LA-ICP-MS was found to be extremely useful for in situ determination of trace elements in real-world carbonate samples (landfill calcites), especially those present in calcite in higher concentrations (Mn, Sr, Ba; < 5% RSD). Less accurate determinations were generally obtained for trace elements present at low concentrations (∼ units of μg g−1). In addition, good agreement was observed between the instrument calibration to MACS and NIST SRM 612 glass for in situ measurements of trace elements in landfill calcites K-2, K-3 and K-4 (differences below 15% relative for most elements). Thus, the application of MACS carbonate reference materials is promising and points to the need for the development of new carbonate reference materials for laser ablation ICP-MS.  相似文献   

13.
We present a multi-element technique for the simultaneous determination of twelve trace elements in geological materials by combined isotope dilution (ID) sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) following simple sample digestion. In addition, the concentrations of fourteen other trace elements have been obtained using the ID determined elements as internal standards. This method combines the advantages of ID (high precision and accuracy) with those of SF-ICP-MS (multi-element capability, fast sample processing without element separation) and overcomes the most prevailing drawbacks of ICP-MS (matrix effects and drift in sensitivity). Trace element concentration data for BHVO-1 (n = 5) reproduced to within 1–3% RSD with an accuracy of 1–2% relative to respective literature values for ID values and 2–3% for all other values. We have applied this technique to the analysis of seventeen geological reference materials from the USGS, GSJ and IAG. The sample set also included the new USGS reference glasses BCR-2G, BHVO-2G and BIR-1G, as well as the MPI-DING reference glasses KL2-G and ML3B-G, and NIST SRM 612. Most data agreed within 3–4% with respective literature data. The concentration data for the USGS reference glasses agreed in most cases with respective data of the original rock powder within the combined standard uncertainty of the method (2–3%), except the U concentration of BIR-1G, which showed a three times higher concentration compared to BIR-1.  相似文献   

14.
We present high precision Ir, Ru, Pt, Pd, Re and rare earth element (REE) determinations by isotope dilution multiple collector-ICP-MS on the Cretaceous-Tertiary boundary sedimentary reference material FC-1. Samples for platinum-group element measurements were digested in Carius tubes followed by acid digestion. The platinum-group elements were subsequently separated by anion exchange chemistry and determined by multiple collector-ICP-MS. The accuracy of the platinum-group element analyses have been verified by comparative analyses of the reference materials WITS-1 and GP13 (sample size 0.5-1 g). Replicate analyses of FC-1 (sample size 0.2 g) exhibit good reproducibility (RSD < 5%) for all the analysed platinum-group elements. REE data also exhibit excellent reproducibility (RSD < 0.5%), which indicates that this sample is homogeneous for the determination of the platinum-group elements and REE at the 0.2 g level.  相似文献   

15.
The Old Woman Mountains in south-eastern California are a Late Cretaceous low-pressure metamorphic terrane where multiple magmatic intrusions generated broad regions of elevated metamorphic temperatures. In the Scanlon Gulch area, two sheet-like, Late Cretaceous granitoid plutons are in contact with the Scanlon shear zone, a 1-km-thick sheet of isoclinally folded and transposed metamorphic rocks. The metaluminous Old Woman granodiorite underlies the shear zone and the peraluminous Sweetwater Wash granite overlies it. Both plutons record emplacement ages of ∼74 Ma. Thermobarometry and phase relations in the shear zone suggest that peak metamorphism was at 650 ± 50† C and 4.3 ± 0.5 kbar. Late Cretaceous metamorphic temperatures were less elsewhere in the Old Woman Mountains, away from the intrusions.
One-dimensional thermal models are used to investigate how differences in the time between the emplacement of plutons would affect the thermal evolution of the central Old Woman Mountains. The prediction of a thermal history inferred from petrological and thermochronological data requires the rapid emplacement of the two plutons around the shear zone; simulations with delays of more than 1 Myr in the emplacement of the second pluton failed to predict peak metamorphic temperatures. Calculations which consider only the emplacement of a single pluton yield metamorphic temperatures that are too low. The time separating the intrusions is by far the most sensitive parameter in the calculations; assumptions concerning the treatment of the initial geothermal gradient and the latent heat of crystallization have relatively small effects on the predicted thermal histories. Our results suggest that for certain geometries, relatively short-lived magmatic events involving rapid emplacement of multiple intrusions can produce low-pressure metamorphism.  相似文献   

16.
It is argued that the current division between field sampling and chemical analysis is counterproductive in terms of ensuring that geochemical measurement results are fit for their intended purpose. An integrated approach to the whole measurement process has many advantages including no dependence on the two assumptions that either the samples are necessarily representative if taken with a correct protocol, or that the measurement results can be assumed to be true values of chemical concentration. The measurement results then require values of measurement uncertainty, including that from sampling as well as from chemical analysis. This enables the user of the measurement results, rather than the producer, to judge their fitness for a specific purpose. Case studies are used to illustrate the practicality and benefits of this new approach, including the use of measurement results with optimal, but relatively high, levels of uncertainty to make reliable decisions. This contrasts with the traditional assumption that pursuit of the lowest possible measurement uncertainty is the best approach.  相似文献   

17.
多接收电感耦合等离子体质谱(MC-ICP-MS)的广泛应用使过渡金属元素同位素地球化学的研究近年来获得蓬勃发展.利用元素双稀释剂法对钼同位素值进行校正,目前可以获得±0.1‰(2σ)的测试精度.自然界中钼同位素分馏δ98/95Mo可达~3‰,其分馏机制与环境的氧化-还原状态有关.在氧化环境下钼以MoO2/4-的形式与锰...  相似文献   

18.
地应力测量与监测技术实验研究——SinoProbe-06项目介绍   总被引:2,自引:0,他引:2  
固体地壳的应力状态是地壳的最重要的性质之一.地壳表面和内部发生的各种构造现象及其伴生的各种地质灾害都与地壳应力的作用密切相关.地应力测量与监测不仅为深入认识地震的孕育和发生机制,进而为强震预测提供重要的科学依据,而且也是地球动力学基础研究的重要组成部分,此外,还将为国家重大工程建设,如深埋隧道、水电工程、深部能源开采、...  相似文献   

19.
Mass-Transport Complexes (MTCs) are important components of deep-water systems, and widely distributed in continental margins and lake basins. Understanding MTCs is helpful for expanding the targets of deep-water hydrocarbon exploration and for evaluating geological risks of subsea engineering. Typical MTCs consist of three parts: the head tension area, body slip area, and toe compression area. During the transportation of MTCs, these three domains come into being successively. MTCs can be classified into three types: slide rock, slump rock, and debris rock, based on the sediment transport process and fluid properties, and they respectively correspond to elastic deformation, elastic and plastic deformation and plastic deformation stages. In 3D seismic plan, according to the direction of sediment flow (the slope direction), some depositional elements of MTCs, such as head cliffs, body folds, and toe squeeze ridges, can be clearly identified in proper order, and in seismic profiles MTCs are characterized by weak-medium amplitude reflections, mound-like shapes, and irregular top/bottom interfaces. In conventional log data, MTCs are commonly responded as abrupt shifts at their top/bottom interfaces. In outcrop data, MTCs have several kinds of sedimentary structures, such as massive textures, sliding folds, and mud lumps. Compared with turbidites, MTCs have many distinct characteristics. For example, MTCs are deposited from sediments transported through a "frozen" manner and have an "elongate-fan-like" slope morphology, a relative large thickness. Furthermore, MTCs can be characterized by no obvious features of grading differentiation and relatively large stratigraphic dips.  相似文献   

20.
地质流体:多学科技术和概念的相互渗透——第二届国际沉积盆地和造山带流体演化、运移和相互作用大会简介陈红汉(中国地质大学武汉430074)关键词地质流体流体演化、运移和相互作用定年和定时分类号P511会议概况“第二届国际沉积盆地和造山带流体演化、运移...  相似文献   

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