Elemental composition x-ray fluorescence analysis with a TES-based high-resolution x-ray spectrometer

The accurate analysis of the elemental composition plays a crucial role in the research of functional materials.The emitting characteristic x-ray fluorescence(XRF)photons can be used for precisely discriminating the specified element.The detection accuracy of conventional XRF methodology using semiconductor detector is limited by the energy resolution,thus posing a challenge in accurately scaling the actual energy of each XRF photon.We adopt a novel high-resolution x-ray spectrometer based on the superconducting transition-edge sensor(TES)for the XRF spectroscopy measurement of different elements.Properties including high energy resolution,high detection efficiency and precise linearity of the new spectrometer will bring significant benefits in analyzing elemental composition via XRF.In this paper,we study the Ledge emission line profiles of three adjacent rare earth elements with the evenly mixed sample of their oxide components:terbium,dysprosium and holmium.Two orders of magnitude better energy resolution are obtained compared to a commercial silicon drift detector.With this TES-based spectrometer,the spectral lines overlapped or interfered by background can be clearly distinguished,thus making the chemical component analysis more accurate and quantitative.A database of coefficient values for the line strength of the spectrum can then be constructed thereafter.Equipped with the novel XRF spectrometer and an established coefficient database,a direct analysis of the composition proportion of a certain element in an unknown sample can be achieved with high accuracy.

Glancing incidence x-ray fluorescence spectrometry based on a single-bounce parabolic capillary

Glancing incidence x-ray fluorescence spectrometry using a single-bounce parabolic capillary is proposed for the analysis of layered samples.The divergence of the x-ray beam was 0.33 mrad.In this paper,we used this instrumental setup to analyze a Si single crystal and a 50 nm HfO_(2) single-layer film deposited on a Si substrate.

Quantitative energy-dispersive X-ray fluorescence analysis for unknown samples using full-spectrum least-squares regression

The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.

Elemental and proximate analysis of coal by x-ray fluorescence assisted laser-induced breakdown spectroscopy

Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.

Impact of Different Grinding Aids on Standard Deviation in X-Ray Fluorescence Analysis of Cement Raw Meal

X-ray fluorescence (XRF) analysis utilizes particle size which is resulted from milling of a material. The milling ensures uniform and fine grained powder. The finer and more uniform the particle size is, the better the result and easier it is for material quality control. To ensure uniformity in particle size and finer powder, a comparative analysis was conducted with different grinding aids and pressed pellet method was used in obtaining analysis results. Pressed pellets of cement raw meal sample milled with different grinding aids (graphite, aspirin and lithium borate) were subjected to XRF. Graphite produced better particle size uniformity with a corresponding standard deviation that made quality control of raw meal easier and better than aspirin and lithium borate.

X-RAY FLUORESCENCE SPECTRA ANALYSIS ON THE STRUCTURE AROUND Ti^(4+) OF BaO-SiO_2-B_2O_3-TiO_2 SYSTEM GLASSES

The structure around Ti^(4+) in Bao-SiO_2 -B_2O_3-TiO_2 had been studied by X-ray fluorescence spectra. The results show that the Ti^(4+) mainly exists in the [TiO_4] and enters the network of [SiO_4]. [TiO_4] has the tendency to change to [TiO_6] with the increase of TiO_2 con-tent. When the TiO_2 content increases to about 20mol% the tendency reaches its maximum.

Determination of Optimum Conditions for X-Ray Fluorescence Analysis Using Coupling Equations

Coupling equations used to calculate the chemical composition of substances by X-ray fluorescence analysis can be classified as empirical, theoretical or semi-empirical based on the method for determining the coefficients of the calibration function. The advantages and disadvantages of each class of equations are discussed. Recommendations for the selecting the optimum conditions for determining empirical correction coefficients and their control during analysis are provided.

Influence of crystal materials on the synchrotron X-ray fluorescence analysis:a study of crystal and amorphous clinopyroxene

Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will seriously affect the X-ray fluorescence analysis. In order to avoid the influence of diffraction, the best way to solve it is to use the monochromatic source, or to have a collimating slit between sample and Si(Li) detector.

In situ analysis of trace elements in metalloproteins of human liver by synchrotron radiation X-ray fluorescence

A method using synchrotron radiation X-ray fluorescence analysis to in situ determine trace elements during protein electrophoretically separating process was established. The distribution of elements in protein bands for human liver cytosolic sample separated by SDS-PAGE was analyzed a-long polyacrylamide gel. The results showed that the protein fraction of peak III in cvtosol was mainly composed of metal ion Zn-associated proteins, being in agreement with that given by atomic absorption spectrometry. Thus, it demonstrated the feasibility of this novel technique for in situ analysis of trace elements in protein bands.

Quantitative analysis results of CE-1 X-ray fluorescence spectrometer ground base experiment

As the nearest celestial body to the earth, the moon has become a hot spot again in astronomy field recently. The element analysis is a much important subject in many lunar projects. Remote X-ray spectrometry plays an important role in the geochemical exploration of the solar bodies. Because of the quasi-vacuum atmosphere on the moon, which has no absorption of X-ray, the X-ray fluorescence analysis is an effective way to determine the elemental abundance of lunar surface. The CE-1 X-ray fluorescence spectrometer （CE-1/XFS） aims to map the major elemental compositions on the lunar surface. This paper describes a method for quantitative analysis of elemental compositions. A series of ground base experiments are done to examine the capability of XFS. The obtained results, which show a reasonable agreement with the certified values at a 30% uncertainty level for major elements, are presented.

Determination of F,S(total),and Cl in the Calcite Rich Limestone and Marbles by WD-XRF Spectrometry

Determining the contents of F,S(total),and Cl in the studied samples of the limestone and marbles with high calcite contents was carried out by the nondestructive method of WDXRFS(Wavelength Dispersive X-ray Fluorescence Spectrometry).All measurements were performed in a vacuum condition using a WDXRF spectrometer S8 TIGER(Bruker AXS,Germany).The studied samples have wide ranges of F,S(total),and Cl contents,and high concentration of calcite(89.5%-99%).Main objective of this research is to develop WDXRF(WD X-ray fluorescence)technique for the determination of F,S(total),and Cl.The calculated values of the ILD(instrumental limit of the detection)were within the interval from 3 for S(total)to 37 for F mg/kg.The repeatability was found to be satisfactory with the relative standard deviations lower than 7%.

Source identification of individual PM_(2.5) particles in Shanghai air in the winter of 2007 with synchrotron X-ray fluorescence microprobe

In order to further understand the sources of PM2.5 in Shanghai air, the synchrotron X-ray fluores- cence microprobe at the BL-4A Beamline of Photon Factory of High Energy Accelerator Research Organization, Japan, was applied to analyze the individual PM2.5 particles collected from Shanghai air in the winter of 2007. Eight categories of emission sources were recognized in these individual particles. The source identification shows that most of the analyzed PM2.5 particles are derived from vehicle exhaust and metallurgical emissions. This suggests that the important emission sources of PM2.5 in Shanghai air would be vehicle exhaust and metallurgical activities.

X射线荧光光谱分析熔融法制样的系统研究

对X射线荧光光谱(XRF)分析的熔融法制样进行了系统地总结。内容包括熔剂的选择、氧化剂的选择、硫化剂的选择、重吸收剂的选择、脱模剂的选择,给出了氧化物、碳酸盐、硫化物、铁合金、石墨材料、铜精矿等几种典型样品熔融制备玻璃片的方法。介绍了铂黄合金坩埚和铸模的保养,而且对制备硼酸盐熔融玻璃片遇到的问题及解决办法都做了详细的说明,此外,还对3种不同类型的熔融设备及其特点做了介绍。研究内容对X射线荧光光谱分析工作者的熔融制样操作有一定指导意义。

高灵敏度原子荧光光谱系统应用于砷、硒形态分析的研究

将实验室自制的高灵敏度原子荧光光谱系统与色谱分离、在线紫外光前处理装置联用，实现了元素形态的液相色谱分离、在线紫外消解、蒸气发生及原子荧光光谱测定，并以砷、硒两元素为例对系统的分析性能进行研究。样品通过加热混旋提取、离心、过滤，使用反相色谱柱并以5.0mmol／L磷酸氢二铵缓冲溶液（pH5.7）-0.5mmol／L四丁基溴化铵（TBAB）-1％甲醇为流动相进行分离；三价砷（AsO3-3）、二甲基砷（DMA）、一甲基砷（MMA）、五价砷（AsO3-4）可在7min内进行分离和测定，硒代胱氨酸（SeCys）、硒代蛋氨酸（SeMet）、四价硒（SeO2-3）、六价硒（SeO2-4）的测定约需11min。在优化实验条件下，方法检出限（DLs，S／N=3）为0.08～0.74μg/L；相对标准偏差（RSD，n=7）为1.4％～7.9％，实际样品的加标回收率为82.5％～116.596；砷、硒各形态在0.28～40.0μg/L和0.38～80.0μg/L范围内线性良好。建立的联用系统稳定性好、检出限低，可实现样品中低浓度砷、硒形态的准确测定。

原子荧光法测定二丁基二月桂酸锡中锡含量

经氧化、分解及消化后,二丁基二月桂酸锡转化成无机锡,分别采用常规化学滴定法、电感耦合等离子质谱法(ICP-MS)及原子荧光光谱法(AFS)测定二丁基二月桂酸锡中的锡含量,结果表明这3种测试手段所测数值基本一致。较其他两种方法而言,原子荧光光谱法具有简便、快速、准确、灵敏度高等特点。针对原子荧光光谱法的加标回收实验结果为99.2%～100.8%,表明该法测定的结果准确可靠,适合作为测定二丁基二月桂酸锡中锡含量的常规检测方法。

基于判别分析的X射线荧光烟叶产地识别应用

烟叶品质的优劣不仅与品种、生长条件有关,还与其原产地的土壤及生长环境有着较大的关联.根据不同产地烟叶中金属元素分布的差异,提出了利用X射线荧光光谱技术快速检测出烟叶中各种金属元素的分布,结合判别分析法对烟叶产地进行识别的研究.首先对不同产地样品的金属元素的平均值进行分析,发现不同产地烟叶样品间存在较大差异;利用SPSS软件对其中样品数较多的4个地区的烟叶样品进行逐步判别分析并建立判别分析模型,当选入自变量的元素包括Cd,Rb,Ba,As,S等6种元素时,建立的判别函数判别回代准确率为92.9%,交互验证的准确率为90.5%,说明应用X射线荧光分析法来鉴别不同产地的烟叶具有较强可行性.

高锰铁矿石分析方法研究

对X荧光光谱熔融法(钴内标)分析含锰高类的铁矿石进行了研究、探讨,对导致TFe仪器分析结果偏高的原因进行了分析,解决了该方法分析此类铁矿石存在的不足,提高了荧光分析的准确度。

X射线荧光光谱仪在铝土矿分析中的应用

选取XRF法对铝土矿中Al2 O3 、SiO2 、Fe2 O3 、TiO2 、CaO、K2 O等组分进行日常分析 ,采用粉末压片制样和经验系数法校正基体效应 ,建立了元素分析的数学模型 ,起到了快速分析。

XRFA直接测定高冰镍中镍、铜、钴、铁和硫

采用粉末压片法制样,X射线荧光光谱法直接测定高冰镍中镍、铜、钴、铁和硫等5个元素。使用德国SIEMENS SRS300型顺序式X射线荧光光谱仪,经验系数法校正元素间效应。其分析范围是:Ni40％～56％,Cu20％～30％,Co0.4％～0.9％,Fe2.0％～5.0％,S20％～26％。分析结果与化学法相符,方法准确、简便、快速,成本低,精密度高,各元素分析标准偏差均小于0.08。适于高冰镍的日常分析及监控高冰镍冶炼的中间产品。

显微荧光光谱原位测定红树植物根表面微区中的蒽

自行搭建显微荧光光谱分析(Microscopic fluorescence spectrometric analysis,MFSA)系统,并将其用于吸附于红树植物秋茄(Kandelia obovata,K.obovata)和白骨壤(Avicennia marina,A.marina)根表面微区中蒽(Anthrancene,Ant)的原位测定。在同步扫描模式下,以波长差为60 nm,吸附于K.obovata和A.marina根表面微区中Ant(5.3 pg/μm2)的荧光信号有最大信噪比(5.5和6.8)。所建方法的线性范围分别为5.3~63.2 pg/μm^2和10.5~52.6 pg/μm^2,检出限分别为1.1和5.5 pg/μm^2,相对标准偏差均小于12.5%(n=9),加标回收率分别为98.1%~117.0%和81.2%~110.9%。结果表明,搭建的MFSA系统具备原位获取植物根表面微区Ant荧光光谱定量信息和荧光图像信息的能力。