X射线荧光光谱在物证鉴定中的应用进展

作为一种常用的元素分析方法,X射线荧光光谱（XRF）技术具有分析范围广、检测速度快、不损耗样品等优点,被广泛应用于各类痕迹物证的检验鉴定。本文简要介绍了XRF技术的发展现状,重点阐述了这项技术在国内外物证鉴定领域的应用进展,并对当前研究中的不足以及进一步的发展做了简要展望。     

Sr元素X荧光快速分析方法

为了实现Sr元素的快速、准确测量,讨论了现场X荧光分析方法(XRF),测量得到Sr元素特征X射线全能峰的峰面积,采用基于傅里叶变换的本底估计方法扣除散射本底,计算得到Sr元素的含量。结果表明,XRF法测得Sr的含量与实验室分析结果的平均相对误差为-9.3%,XRF法对现场快速分析Sr含量有指导意义。     

分散液相微萃取-X射线荧光法快速同时分析水溶液中的重金属

自主建立了一种利用分散液相微萃取技术同时富集水溶液中铅、镉和汞三种重金属离子的X射线荧光多元素同时分析方法。方法首先以二乙基二硫代甲酸钠(Na-DDTC)为络合剂,在pH 4.0条件下,络合剂与水溶液中铅、镉和汞离子同时络合,形成金属络合物;再采用以丙酮为分散剂、四氯乙烯为萃取剂的分散液相微萃取方法对水溶液中金属络合物同时进行百倍的萃取富集,最后采用X射线荧光光谱仪对萃取溶液中铅、镉和汞元素同时进行定性定量分析,整个分析过程数分钟内完成,3个元素方法检出限均可达0.1 mg/L。该方法在一定程度上弥补了XRF本身检出限高的问题,扩展了XRF在水相中痕量铅、镉和汞元素检测中的进一步应用。     

中国XRF历史发展的相关资料征集启事

X射线荧光光谱(XRF)技术是当今最重要的无机分析技术之一,拥有无污染的独特优势,使得它在未来的"环境友好"分析实验室建设中具有广阔的发展前景。XRF仪器自1948年问世以来,已有66年的发展历史,在我国的应用研究也已经历了50多年。为记载我国XRF的历史发展,国内多家XRF实验室提议共同编写一本记载我国XRF发展历程及成果的专著。     

中国XRF历史发展的相关资料征集启事

X射线荧光光谱(XRF)技术是当今最重要的无机分析技术之一,拥有无污染的独特优势,使得它在未来的"环境友好"分析实验室建设中具有广阔的发展前景。XRF仪器自1948年问世以来,已有66年的发展历史,在我国的应用研究也已经历了50多年。为记载我国XRF的历史发展,国内多家XRF实验室提议共同编写一本记载我国XRF发展历程及成果的专著。为此,向各科研单位XRF实     

X 射线荧光光谱强度校正经验系数法测定轻混合稀土氧化物

混合稀土中单个稀土元素的定量分析是一个较复杂的问题。采用 X 射线荧光光谱分析高含量元素具有精密度高的优点,但存在基体效应对分析准确度的影响。因此,如何克服基体效应成为建立一个可靠分析方法的关键。关于     

中国XRF历史发展的相关资料征集启事

X射线荧光光谱(XRF)技术是当今最重要的无机分析技术之一,拥有无污染的独特优势,使得它在未来的"环境友好"分析实验室建设中具有广阔的发展前景。XRF仪器自1948年问世以来,已有66年的发展历史,在我国的应用研究也已经历了50多年。为记载我国XRF的历史发展,国内多家XRF实验室提议共同编写一本记载我国XRF发展历程及成果的专著。为此,向各科研单位XRF实验室、国内外仪器设备厂家及相关从业人员征集材料,欢迎各实验室、厂家及个人积极参与,以使中国的XRF事件在书中得到更全面的反映。     

元素薄膜标样计量溯源技术路线探讨及验证

元素薄膜标样是X射线荧光光谱(XRF)法用于大气颗粒物样品中无机元素测定的必备实验用品。开发满足计量溯源要求的国产元素薄膜标样对于建立大气颗粒物元素XRF分析校准曲线,降低基层实验室用户采购薄膜标样费用具有重要意义。同时采用基于薄膜酸消解的等离子体发射光谱(ICPOES)和基于直接测定的波长色散X射线荧光光谱(WD-XRF)两种方法,提出了对元素薄膜样品进行定值的技术路线,并以稀土元素薄膜样品的定值为例进行了验证。用镀膜固体粉末材料探讨了酸消解体系和ICP-OES分析方法的可行性,实验结果表明,稀土元素回收率93.3%～99.7%。基于酸消解-ICPOES测定值建立的WD-XRF校准曲线具有良好线性关系,各元素相关系数0.9978～1.000。实现了WD-XRF测定结果应满足计量溯源要求的预期目的。基于同一批元素镀膜样品X射线荧光强度数据精密度,对镀膜工艺一致性进行了考察,相对标准偏差0.16%～1.5%。测量结果不确定度的评估数据表明,对于低含量元素薄膜样品,ICP-OES拟合模型误差是测量结果不确定度的主要分量。实验结果为后续开展元素薄膜标样协作定值奠定了基础。     

利用控制图评价X射线荧光光谱法测定铁矿石成分分析系统的稳定性

<正>目前,X射线荧光光谱法(XRF)广泛应用于铁矿石中成分分析[1-3]。铁矿石杂质元素硅、铝和磷作为主要的计价指标,在铁矿石贸易中具有重要的意义。因此,在实验室日常检测中,需对XRF测定铁矿石杂质成分分析系统进行全面的质量控制,保证分析方法的稳定性和准确性。质量控制图[4]可对过程的关键质量特性值进行测定、记录、评估并监测过程是否处于控制状态,已在生产和实验室检测质量控制中得到了广泛的应用[5-7]。铁矿石检验多采用     

X射线荧光光谱扫描法在实物地质资料中应用的可行性探讨

实物地质资料的定量无损检测对于地质学研究具有十分重要的意义,在国外x射线荧光光谱（XRF）扫描分析方法在岩芯分析测试方面的应用研究,已取得了十分显著的成果。XRF岩芯扫描分析方法具有分析速度快、无损检测、连续定量测试多元素和样品制备简单等特点,在获取高分辨测试方面更具独特的优势。因此,这一分析方法在实物地质资料分析方面具有极好的应用前景,它能提高分析的准确性和精确度,降低分析测试成本,保护实物地质资料的完整性,加强实物资料的整体性研究,为实物地质数据采集与信息共享提供更加准确的数据。从介绍XRF岩芯扫描分析方法的原理、特点、影响因素、分析结果的校正人手,进而探讨该测试方法在实物地质资料中应用的可行性。     

萤石成分分析方法的标准现状与研究进展

萤石是一种重要的战略性非金属矿产资源,本文对中国国家标准、行业标准、国际标准（ISO）、美国标准（ASTM）以及俄罗斯标准（GOST）中的萤石成分分析标准方法的现状进行了介绍。对近年来X射线荧光光谱法（XRF）、电感耦合等离子体发射光谱法（ICP-AES）、电感耦合等离子体质谱法（ICP-MS）、激光诱导击穿光谱法（LIBS）等技术在萤石成分分析中的应用以及标准物质/标准样品研制情况进行了总结和评述。文章认为,萤石分析测试技术标准体系相对完备,XRF、ICP-AES、ICP-MS等仪器分析测试技术已普遍应用于萤石样品实验室分析,建议尽快研究并建立萤石中稀土等微量元素测定的标准方法,并开展相应标准物质/标准样品的研制,同时应大力开展原位在线分析技术的研究与开发,以适应工业在线自动化监测的需求,LIBS与在线XRF技术联合在萤石在线分析方面具有良好的应用潜力。     

Comparative methods for determination of rare earths in geological and mineral samples

Particle induced X-ray emission (PIXE) has been used for the quantitative analysis of rare earth elements (REE) in thick targets prepared from geological and mineral samples. Measurements were made with 1 and 3 MeV proton beams. For comparison, determination of the same elements was made by X-ray fluorescence (XRF) using a²⁴¹Am annular source. Minimal detectable limits (MDL) have been estimated for the two situations. Neutron activation analysis (NAA) has also been used for the determination of REE at the ppm level.     

Determination of traces of rare earth elements in geological samples

A procedure for the determination of traces of rare earth elements by inductively coupled plasma-optical emission spectrometry (ICP-OES) and X-ray fluorescence spectrometry (XRF) is presented. The samples are decomposed either by fusion with lithium tetraborate or by acid attack in a microwave oven. Separation of the rare earth elements from accompanying elements is achieved by anion exchange. For the determination by ICP-OES the samples are injected in hydrochloric acid solution, for the determination by XRF the rare earth element traces are co-precipitated with rhodizonate and tannin and measured as a thin film on a membrane filter. All preconcentration steps have been optimized and tested using radiotracers. Furthermore the rare earth element contents of some international standard reference rocks have been determined; the results are compared to the certified values and other values given in the literature. The procedure is applied to a series of petrographically identical metabasites with different degrees of metamorphism to show the mobility of those ions under metamorphic conditions.     

Fast determination of trace elements on aerosol-loaded filters by X-ray fluorescence analysis considering the inhomogeneous elemental distribution

X-ray fluorescence (XRF) analysis was successfully applied for the determination of Ca, Cu, Fe, Mn, Ni, Pb, V and Zn on aerosol filters with a diameter of 150 mm. Ambient aerosol was collected on quartz-fibre filters by Digitel high-volume samplers. For XRF analysis three small filter pieces with a diameter of 32 mm were cut out of each filter, considering the radial dependence of elemental distribution on the filter. Elemental concentration decreases by 8–10% from the centre to the outer circle for coarse mode elements. Distribution of fine mode elements display only small radial dependence (2–4%). Results of quantitative analysis by XRF were compared with atomic spectrometric methods (GF-AAS, ICP-OES). The good agreement between the methods confirmed the application of XRF spectrometry for routine analysis of filter samples loaded with ambient aerosol.     

Fast determination of trace elements on aerosol-loaded filters by X-ray fluorescence analysis considering the inhomogeneous elemental distribution

X-ray fluorescence (XRF) analysis was successfully applied for the determination of Ca, Cu, Fe, Mn, Ni, Pb, V and Zn on aerosol filters with a diameter of 150 mm. Ambient aerosol was collected on quartz-fibre filters by Digitel high-volume samplers. For XRF analysis three small filter pieces with a diameter of 32 mm were cut out of each filter, considering the radial dependence of elemental distribution on the filter. Elemental concentration decreases by 8-10% from the centre to the outer circle for coarse mode elements. Distribution of fine mode elements display only small radial dependence (2-4%). Results of quantitative analysis by XRF were compared with atomic spectrometric methods (GF-AAS, ICP-OES). The good agreement between the methods confirmed the application of XRF spectrometry for routine analysis of filter samples loaded with ambient aerosol.     

Identification of glass and ceramics by X-ray fluorescence analysis with a pyroelectric X-ray generator.

Applications of X-ray fluorescence (XRF) analysis with a pyroelectric X-ray generator are presented. Glass and ceramics were analyzed with this novel X-ray generator to examine its capability for analyzing nonmetallic inorganic material. Although the power of X-ray output was a few orders of magnitude lower than conventional X-ray tubes, many elements such as Si, K, Ca, Ti, Cr, Fe, Zn, Sr, Ba, and Pb were detected in glass and ceramic samples. Light elements such as Na, Mg, and Al were not detected because of the low fluorescence yield and the absorption of fluorescent X-rays in air. The elements detected or the relative peak intensities of the elements were different from each other, and the samples analyzed were identified by the XRF spectrum, notwithstanding the low power of the X-ray output. This novel device showed the sufficient capability for preliminary screening before strict identification of analytes. The pyroelectric X-ray generator can also be used to analyze large samples that cannot be put into ordinary XRF spectrometers because the device has no dimensional limitation of analytes.     

Analysis of archaeological artefacts: PIXE, XRF or ICP-MS?

Elemental analysis of ancient artefacts is of considerable benefit to the field of Archaeology and of general interest to earth scientists. Several techniques are currently available for this purpose, and in this paper the capabilities of PIXE (Particle Induced X-ray Emission), XRF (X-ray Fluorescence) and ICP-MS (Inductively Coupled Plasma - Mass Spectrometry) were evaluated to establish which of these instrumental methods was best suited especially for routine on-line usage. The elements of interest discussed in this paper are useful in archaeological provenance studies.     

Trends,applications and results in X-ray fluorescence analysis

X-ray fluorescence (XRF) has reached a mature state and represents a powerful analytical tool for the qualitative and quantitative determination of almost all the chemical elements in a sample. Standard XRF methods as well as special techniques to improve the detection limits will be presented, emphasizing the versatility of the method. With modern instrumentation the detectable number of elements ranges from Be to U. The minimum detectable quantities under optimizied excitation and detection conditions for medium Z elements are a few hundred femtograms. Other features like rapid analysis because of the multielement capability and in some cases the nondestruction of the sample are advantageous for a wide field of applications.     

Determination of rare earth elements and thorium in britholite ore by energy dispersive X-ray fluorescence spectrometry

A radioisotope-excited X-ray fluorescence technique is applied for the determination of thorium and rare earth elements in britholite ore from Canada. An annular source of⁵⁷Co is employed for excitation of characteristic K X-rays of thorium and rare earth elements. The peak ratios of lanthanides were used to remove the difficulties because of overlapping lines at the 33–50 keV energy region. Matrix effects are examined also in detail and compensated for infinitely thick powdered ore sample. Results obtained in the analysis agree well with recommended values of Canada.     

Measurement of total and photoelectric cross sections of rare earth elements present in compounds for 123.6 keV and 145.4 keV photons

A new, simple and direct method proposed earlier by us has been employed here to measure the total photoelectric cross section of rare earth elements in the range 58 Z 66 present in compounds at 123.6 keV and 145.4 keV photon energies. The K X-ray fluorescence intensities emitted by these elements, from irradiating their compounds by the photons of above energies, are measured using a NaI (Tl) spectrometer system in a 2π geometrical configuration. The K X-ray fluorescence cross sections of the rare earth elements are determined, from which the total photoelectric cross sections are evaluated. Total mass attenuation coefficients of compounds for the K X-ray and the incident radiations respectively have been measured and these values were compared with the corresponding theoretical values and a good agreement between them is obtained.