The determination of lead in total suspended air particulates by x-ray fluorescence spectroscopy

A method has been developed for the measurement of lead in air particulates collected on glass fiber filter paper with wavelength-dispersive x-ray fluorescence spectroscopy (WDXRF). Analyses conducted by both WDXRF and an EPA-approved procedure that employs acid sonication followed by analysis of the extract by atomic-absorption spectroscopy (AAS) shows excellent agreement between the two methods. WDXRF calibration was accomplished with standards prepared from known additions of Pb to unexposed glass fiber filter discs. Method equivalency has also been demonstrated by the analysis of several reference materials and the statistical analysis of quality control data. The WDXRF procedure has also been used to evaluate the distribution of Pb in the particulates across the surface of the filter.     

A method for prompt in situ uranium assay and free acidity determination in uranyl nitrate solutions by density and Raman measurements

A precise and accurate compositional characterization methodology using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry for mixed oxide nuclear fuels is reported. The methodology involves pelletization of standards and samples. The calibration plots were made by plotting the percent intensity of analyte X-ray lines against their amount percent. The relative standard deviation were 0.4% and 0.25%, respectively for uranium and thorium, having U ranging from 2.85 to 4.2 (wt%). The analytical results were compared with chemical analysis method and were in good agreement. The developed WDXRF method is non-destructive, fast and better in comparison to chemical analysis methods.

     

Determination of silicon in biological samples by ICP-OES after non-oxidative decomposition under alkaline conditions.

A non-oxidative alkaline sample digestion procedure using tetramethylammonium hydroxide and a high pressure, microwave assisted autoclave digestion system was developed. The silicon concentrations of the digested samples were measured by inductively coupled axial plasma optical emission spectrometry (ICP-OES). Details of the digestion conditions as well as the optimised instrumental parameters for ICP-OES are described. The method was developed and tested using silicon-spiked ascorbic acid and applied to samples of animal tissue and organs. The total silicon content of two different reference materials, NIST 1577b Bovine liver and BCR 184 Bovine Muscle having neither certified nor informational values for Si was determined. The results obtained are compared with the results of independent methods such as wavelength dispersive x-ray fluorescence spectrometry (WDXRF) and solid sampling electrothermal atomic absorption spectrometry (ETAAS). The method described achieves a limit of detection of 2 mg kg(-1) using 100 mg of solid biological or organic material and covers a concentration range of up to 500 mg kg(-1).     

Stoichiometry determination of (Pb,La)(Zr,Ti)O3-type nano-crystalline ferroelectric ceramics by wavelength-dispersive X-ray fluorescence spectrometry

Analysis of small samples of lanthanum-doped lead zirconate titanate (PLZT) by wavelength-dispersive X-ray fluorescence spectrometry (WDXRF) is presented. The powdered material in ca. 30 mg was suspended in water and collected on the membrane filter. The pure oxide standards (PbO, La₂O₃, ZrO₂ and TiO₂) were used for calibration. The matrix effects were corrected using a theoretical influence coefficients algorithm for intermediate-thickness specimens. The results from XRF method were compared with the results from the inductively coupled plasma optical emission spectrometry (ICP-OES). Agreement between XRF and ICP-OES analysis was satisfactory and indicates the usefulness of XRF method for stoichiometry determination of PLZT.     

Determination of elemental concentration of seed coats of different fruits by using WDXRF spectroscopy technique

Elemental concentrations of five different seed coats of fruit seeds were determined by using wavelength-dispersive X-ray fluorescence (WDXRF) technique. Basic aim of this study is to measure mass percentages of macro, micro and trace elements in samples. Besides, analyze results have been commented in terms of correlation between the same element types in seed coats of different fruits. Some interesting results have been obtained about element quality and quantity.     

Analysis of non-organic elements in plant foliage using polarised X-ray fluorescence spectrometry

An X-ray fluorescence (XRF) method for the rapid and non-destructive analysis of 30 non-organic elements in plant leaves over five orders of magnitude concentration from several percentage of dry weight to sub-milligram per kilogram, is described. There is a growing need for a simple method of monitoring non-organic trace elements in plant material, especially those which accumulate in soils with application of fertilisers, both inorganic and biosolids. Earlier attempts to use XRF for the analysis of plant material suffered from sensitivity loss due to the high background of organic matrices caused by scattering of the X-ray source. We overcome this by using polarised X-ray sources in a Cartesian geometrical arrangement with sample and energy dispersive detector (EDPXRF), a configuration which can achieve an order of magnitude reduction in background compared with unpolarised sources. Further sensitivity gains are made using a high power tube as a source of primary X-rays and for some analytes employing secondary targets for near-monochromatic excitation. Sample preparation is simple involving only pulverising and briquetting of dried samples. Accuracy is evaluated by comparing data obtained for the suite of NIST plant leaf samples (NIST 1515 apple leaves, NIST 1547 peach leaves, NIST 1570a spinach leaves, NIST 1573a tomato leaves and NIST 1575a pine needles) and tobacco leaf standards CTA-OTL-1 and CTA-VTL-2. The data compare well over the whole concentration range and the method provides a rapid analytical tool for monitoring potentially toxic trace elements in all types of foliage with adequate sensitivity for many purposes.     

铝合金建材的X射线荧光分析

用高性能飞利浦PW2424型X射线荧光光谱仪,测定铝合金建材中的Si、Fe、Cu、Mn、Mg、Zn、Ti、Cr、Ni等9个化学元素的含量.给出各元素的干扰校正系数和基体效应校正系数.方法准确、灵敏,稳定性好,速度快.     

Analytical determination of colouring elements and of their compounds in glass beads from graveyards of the Merowings time

428 Monochrome beads from mainly female graves excavated at Groß-Gerau, Pleidelsheim and Weingarten (Germany) were examined by non-destructive methods, i.e. energy-dispersive X-ray fluorescence analysis (EDXRF), wavelength-dispersive X-ray fluorescence analysis (WDXRF) with fundamental parameter evaluation, and X-ray diffraction analysis. The results obtained by EDXRF were compared with those for beads from Donaueschingen and Eichstetten, published in former papers. In most cases the results obtained by WDXRF show very high contents of the colouring compounds, corresponding to a low glass quality. The diffraction measurements show crystalline colouring compounds at the surface of the glass beads that can be characterized as Pb₂SnSbO_6.5 for the yellow beads and as Cu₂O for the ochre beads.     

Determination of Calcium,Phosphorus and Potassium in Leaf Tissues by Extraction with Ethanol-Water Solvent

Abstract

A new method has been developed for the analysis of elements in plant leaves by aqueous-ethanol extraction. The method was initially tested for calcium, potassium and total phosphorus. Very good results were obtained when compared with those of other methods. Extraction is done with a 20% v/v ethanol-water mixture, refluxing the plant material during 15 to 30 minutes. After treatment with activated carbon the solution is filtered through fast quantitative filter paper (Whatman nr. 40). The elements can be analysed as usual, by atomic absorption, flame photometry, etc. The procedure is promising for routine analysis because of its low cost, simplicity of operation, rapidity, safety characteristics and quality of the results. 30 to 40 minutes are sufficient to prepare solution samples from the dried plant material.     

Determination of silicon in biological samples by ICP-OES after non-oxidative decomposition under alkaline conditions

A non-oxidative alkaline sample digestion procedure using tetramethylammonium hydroxide and a high pressure, microwave assisted autoclave digestion system was developed. The silicon concentrations of the digested samples were measured by inductively coupled axial plasma optical emission spectrometry (ICP-OES). Details of the digestion conditions as well as the optimised instrumental parameters for ICP-OES are described. The method was developed and tested using silicon-spiked ascorbic acid and applied to samples of animal tissue and organs. The total silicon content of two different reference materials, NIST 1577b Bovine liver and BCR 184 Bovine Muscle having neither certified nor informational values for Si was determined. The results obtained are compared with the results of independent methods such as wavelength dispersive x-ray fluorescence spectrometry (WDXRF) and solid sampling electrothermal atomic absorption spectrometry (ETAAS). The method described achieves a limit of detection of 2 mg kg^–1 using 100 mg of solid biological or organic material and covers a concentration range of up to 500 mg kg^–1. Received: 27 October 2000 / Revised: 31 January 2001 / Accepted: 2 February 2001     

Analysis of nuclear materials by energy dispersive X-ray fluorescence and spectral effects of alpha decay

Energy dispersive X-ray fluorescence (EDXRF) spectra collected from alpha emitters are complicated by artifacts inherent to the alpha decay process, particularly when using portable instruments. For example, ²³⁹Pu EDXRF spectra exhibit a prominent uranium L X-ray emission peak series due to sample alpha decay rather than source-induced X-ray fluorescence. A portable EDXRF instrument was used to collect qualitative spectra from plutonium and americium, and metal alloy identification was performed on a Pu-contaminated steel sample. Significant alpha decay-induced X-ray fluorescence peaks were observed in spectra obtained from the plutonium and americium samples due to the ²³⁵U and ²³⁷Np daughters, respectively. The plutonium sample was also analyzed by wavelength dispersive XRF (WDXRF) to demonstrate that alpha decay-induced X-ray emission has a negligible effect on WDXRF spectra.     

粉末压片-X射线荧光光谱法测定铜冶炼炉前各种炉渣、冰铜中5种组分

应用X荧光光谱仪结合压片法制样快速测定铜冶炼中炉前的炉渣和冰铜中的铜、铁、二氧化硅、氧化钙及冰铜中各组分的分析。利用手工分析制备质控样品作为标准物质绘制工作曲线,解决了炉前样品没有标准样品的问题。对炉前分析样品基体不稳定带来的背景干扰,采用手工分析对照,不断调整工作曲线进行对照校正,通过质控管理能够满足生产指标控制的要求。分析结果表明,方法的相对标准偏差(RSD)为0.01%~0.28%,测定结果与通用的容量法分析结果对比,结果基本一致。     

铜–铬–锆合金光谱分析用标准物质的研制

以电解铜和铜–铬、铜–锆中间合金为原材料,通过真空熔炼和热锻加工工艺,研制了铜–铬–锆合金光谱分析用标准物质。将样品分成4组,每组85块后,采用金相检验和光电直读光谱仪进行均匀性、稳定性和定值分析。从样品中随机抽取15块进行均匀性检验,经F检验表明,在95%的置信区间范围内样品均匀性良好;稳定性考察12个月,结果表明在考察期间内样品稳定性良好;标准物质样品经国内3家具有分析资质的实验室进行协作定值,并评定了定值结果的不确定。铜–铬–锆合金标准物质样品中Cr,Zr元素的相对扩展不确定度分别为0.015%~0.036%,0.019%~0.033%(k=2)。该标准物质达到了国家标准物质的技术要求,可用于有关铜–铬–锆合金产品中铬、锆元素的方法校准和质量控制。     

Determination of Mg, Ti and Cl in Ziegler-Natta catalysts by WDXRF

A method for determination of Mg, Ti and Cl in Ziegler-Natta (ZN) catalysts by wavelength dispersive X-ray fluorescence (WDXRF) spectrometry was developed. For comparative reasons, Ti was determined by spectrophotometry, Mg by complexometry and Cl by argentometric titration. Direct pressing was shown to be unsuitable for sample preparation due to catalyst decomposition. For Ti and Mg measurements, catalyst samples were calcinated at 1000 °C and pressed at 275 MPa. Their determination by the fundamental parameters based on the Ti Ka line measurement was shown to be equivalent to those results obtained by univariate calibration or by the classical methods. Cl was determined by aqueous extraction, followed by deposition on a support. Chloride loss was observed. Fixation of Cl as AgCl on polytetrafluoroethylene (FHLC) millipore membrane afforded the best results. Nevertheless, measurements by WDXRF were shown to be inferior to those obtained by argentometric titration.     

微波溶样ICP-MS直接测定茶叶中15种痕量稀土元素

本文报道用ＨＮＯ３－Ｈ２Ｏ２微波溶样，不经分离富集，用标准加入ＩＣＰ－ＭＳ法，直接测定茶叶中１５种痕量稀土元素．对微波溶样和等离子体质谱测定条件进行了优化选择．在最佳实验条件下，用本法测定了国家一级茶叶标准物质ＧＢＷ０７６０５中的单一稀土元素，测得值与标准值很好吻合     

Elemental uptake of radish grown near a Municipal Solid Waste dumping site by EDXRF

Radish plant was collected along with root and soil from the nearby area of a Municipal Solid Waste dumping site of the metropolitan city of Kolkata, West Bengal, India and analyzed for a wide range of elements using the EDXRF technique with a ¹⁰⁹Cd point source and a Si(Li) detector. The samples comprized of the root-soil, root and leaves. For quality control purposes, NIST standard reference material (SRM) 1648 Urban Particulate Matter had also been analyzed using the same procedure as for the samples. Concentrations of elements with X-ray energies in the range of 3–20 keV in the soil around the root and their uptake pattern by the root and the leaves have been estimated.     

PIXE and XRF elemental analysis of breakfast cereals consumed in Mexico

Elemental concentrations in breakfast cereals consumed in Mexico were measured using Particle induced X-ray emission with 1.7 MeV protons and X-ray fluorescence with a Rh X-ray tube operating at 35 kV. The specimens, obtained from packages purchased in markets, were freeze dried, ground and pelletized. Standardization was done with tomato, spinach, peach, and orchid leaves NIST standard reference materials, and analytical accuracy verified with NIST 3233 standard reference material (fortified cereal). The concentrations of nine elements did not agree with values quoted in the packages. Therefore, there may be inaccurate official estimations of Mexican population nutrient intakes.     

Analytical procedures for the determination of selected major (Al, Ca, Fe, K, Mg, Na, and Ti) and trace (Li, Mn, Sr, and Zn) elements in peat and plant samples using inductively coupled plasma-optical emission spectrometry

A simple, robust and reliable analytical procedure for the determination of Al, Ca, Fe, K, Li, Mg, Mn, Na, Sr, Ti, and Zn in peat and plant materials by inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed. A microwave heated high pressure autoclave was used to digest powdered sample aliquots (approximately 200 mg) with different acid mixtures including nitric acid (HNO₃), tetrafluoroboric acid (HBF₄) and hydrogen peroxide (H₂O₂). The optimized acid mixture for digestion of plant and peat samples consisted of 3 mL HNO₃ and 0.1 mL HBF₄, in addition to H₂O₂ which was sub-boiled into the PTFE digestion tubes during heating of the autoclave. Using HNO₃ alone, recoveries of Al and Ti were too low by 40 and 160%, respectively, because HNO₃ could not fully liberate the analytes of interest from the silicate fraction of the plant and peat matrix. However, for all other elements (such as Mn, Sr, and Zn), the use of HBF₄ was less critical. The accuracy of the analytical procedure developed was evaluated with peat and plant reference materials of different origin and composition. The ICP-OES instrument was optimized using solutions of plant reference materials considering RF power, nebulizer pressure, auxiliary gas flow and rinse time. Scandium was used as an online internal standard (IS) as it provided accurate results and showed less than 3% drift in sensitivity over time which was lower compared to other potential IS such as Rh (20%) and In (6%). The combination of most sensitive and less sensitive wavelengths allowed to obtain low detection limits and highest possible dynamic range. The achieved procedure detection limits ranged from 0.05 μg g⁻¹ (Li) to 15 μg g⁻¹ (Ca) and allowed a precise quantification of all elements. Comparative X-ray fluorescence spectrometric measurements of solid peat and plant samples generally agreed well with results obtained by digestion/ICP-OES. To overcome interferences caused by Na, K, and Li, a solution of 10 μg g⁻¹ CsCl₂ was successfully used as an ionization buffer. The good agreement between the found and certified concentrations in plant and peat reference materials indicates that the developed analytical procedure is well suited for further studies on the fate of major elements in plant and peat matrices.     

Determination of trace elements in sediment reference materials by monochromatic X-ray excitation X-ray fluorescence spectrometry.

A new reliable analytical method, "Monochromatic X-ray Excitation X-ray Fluorescence Spectrometry", has been proposed. For validating the method, trace elements in sediment certified reference materials were determined. In the method X-ray fluorescence spectra are measured for specimens and pure metals; in addition the mass-attenuation coefficients of the specimens for various X-ray wavelengths are also measured. The data are analyzed by the fundamental parameter method and the uncertainty of the analysis is evaluated. The obtained results were in satisfactory agreement with the certified values within their uncertainties. This method will be applicable to the certification of reference materials, in the field of which reliable results with uncertainty statements are required.     

X射线荧光光谱法测定化探样品中主、次和痕量组分

采用粉末样品压片制样,用PW2440X射线荧光光谱仪对化探样品中氯、溴、硫、氧化钠、氧化镁、三氧化二铝、二氧化硅、磷、氧化钾、氧化钙、钛、锰、三氧化二铁、钴、铌、锆、钇、锶、铷、铅、钍、锌、铜、镍、钒、铬、钡、镧、铈、钕、钪、镓、砷、铪等34个组分进行测定。讨论了微量元素的背景选择和谱线重叠校正及氯测定的问题。使用经验系数法和康普顿散射线作内标校正基体效应,经标准物质检验,分析结果与标样值吻合,用GBW 07308国家一级标准物质作精密度试验,统计结果RSD（n=12）除砷、钒、镍、铜〈6．0％,溴、硫、铈、铪、钕、钪、氧化钠、镧、铬、钴和钍〈14．0％以外,其余各组分均小于3．0％。