Preparation and Evaluation of a Chrysotile Asbestos-containing Standard Material for Validating X-Ray Diffractometric Quantitation

Asahi, Tomoharu; Kobayashi, Shinji; Nakayama, Kenichi; Konya, Takayuki; Fujinawa, Go; Nakamura, Toshihiro

doi:10.2116/analsci.27.1217

Cited by 11 publications

(8 citation statements)

References 21 publications

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“…geological samples composed of various minerals). For example, glass beads have been prepared for the analyses of rocks, soils, pottery, and perlite board . As an example, Nakayama et al .…”

Section: Glass Beadsmentioning

confidence: 99%

Approaches to solid sample preparation based on analytical depth for reliable X‐ray fluorescence analysis

Ichikawa

Nakamura

2016

X-Ray Spectrometry

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In this paper, we discuss approaches to prepare solid samples for X-ray fluorescence spectrometry (XRF). Although XRF can be used to analyze major and minor elements in various solid samples including powders and grains without dissolution techniques, to obtain reliable XRF results, the prepared sample must meet certain criteria related to homogeneity, particle size, flatness, and thickness. The conditions are defined by the analytical depth of fluorescent X-rays from analytes, and the analytical depth can be estimated from the X-ray absorption related to the energy of each X-ray and the composition and density of the sample. For example, when the sample flatness and particle size are less than the analytical depth and the sample possesses homogeneity within a depth less than the analytical depth, the XRF results are representative of the entire sample. Furthermore, an appropriate sample thickness that is larger than the analytical depth or constant can prevent changes in fluorescent X-ray intensity with variations in sample thickness. To obtain accurate and reproducible measurements, inhomogeneous solid samples must be pulverized, homogenized, and prepared as loose powder, powder pellets, or glass beads. This paper explains the approaches used to prepare solid samples for XRF analysis based on the analytical depths of fluorescent X-rays.

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Section: Glass Beadsmentioning

confidence: 99%

Approaches to solid sample preparation based on analytical depth for reliable X‐ray fluorescence analysis

Ichikawa

Nakamura

2016

X-Ray Spectrometry

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“…The crystalline purities of all the chemical reagents were determined by powder XRD/Rietveld refinement, and each diffraction intensity was corrected by the crystalline purities according to a previously reported method. 20,21) For example, the crystalline purities were measured as follows: hematite, 98.7%; magnetite, 94.0%; and eskolaite, 92.3%.…”

Section: Reagents For Standardsmentioning

confidence: 99%

“…These results indicate that eskolaite is the most suitable internal standard material for the XRD analysis of sintered ore. Asahi et al 20,21) reported that the mass absorption coefficient of an internal standard should be close to that of the analyte. The mass absorption coefficient of eskolaite (177 cm 2 .…”

Section: Selection Of the Internal Standard Materialsmentioning

confidence: 99%

Crystalline Phase Quantitation of Sintered Ore with Powder X-ray Diffractometry with Rietveld Refinement

et al. 2016

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X-ray diffractometry (XRD) with Rietveld refinement was applied to the crystalline phase analysis of two certified standard sintered ores (JSS 851-2 and JSS 851-5) and an industrial sintered ore (SO-1). An eskolaite (Cr 2 O 3 ) powder was mixed at 10 mass% with each sintered ore sample as an internal standard to correct for the effect of amorphous phase and unknown crystalline phases. The results of Rietveld refinement for JSS 851-2 were 23.0 mass% hematite, 29.5 mass% magnetite, 39.8 mass% silico ferrites of calcium and aluminum, 5.6 mass% dicalcium silicate, and 2 mass% amorphous phase, and these values are within the range previously reported for its phase composition. The elemental concentrations calculated from the crystalline compositions using Rietveld refinement of the three sintered ore samples were also in good agreement with the certified values and those from X-ray fluorescence analysis. A calibration curve method and a diffraction-absorption method for crystalline phase quantitation were used to validate the results of the powder XRD/Rietveld method, and the three results agreed well. The present method enables reliable determination of not only the major crystalline phases but also the amorphous phase present in the sintered ore.KEY WORDS: sintered ore; X-ray diffractometry; Rietveld refinement; internal standard.

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“…These methods yield the analysis of the total carbon in cast iron; however, they do not allow the separative analysis of graphite and its polymorphism. X-ray diffractometry, which is used for the analysis of crystalline materials, such as zinc oxide, 18) asbestos, 19) calcium sulfate in air particles, 20) cement, 21) refractory materials, 22) and sintered ore 23) can be used to distinguish the analysis of different crystal phases of graphite and its polymorphism. Therefore, we propose a method to easily provide separative determination for different types of graphite by X-ray diffraction (XRD).…”

Section: Introductionmentioning

confidence: 99%

Phase Quantification of Regular and Turbo-stratified Graphite in Cast Iron by X-ray Diffractometry/Rietveld Refinement

et al. 2021

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A method to quantify regular graphite and turbo-stratified graphite (TS-graphite) forming the free carbon in ductile cast iron was developed using X-ray powder diffractometry. Iron in accurately sampled 2-4 g of the ductile cast iron powder was decomposed using hydrochloric acid without heating, and the residue was centrifugally separated. Graphite, TS-graphite, wustite (FeO), and amorphous silicate were identified in the residue. Calibration-standard mixtures were prepared by mixing corundum (α-Al 2 O 3 ), griceite (LiF), and graphite powder which showed the most similar full-width at half-maximum value of (002) line to that of graphite in the ductile cast iron sample. The calibration curve of graphite showed good linearity, with a range of 0-200 mg corresponding to the 0-5.0 mass% of graphite in the 4.00 g of the cast iron sample. The quantitative value of total graphite in the ductile cast iron sample was 3.17 mass% with 8.0% of relative standard deviation for n = 5. The peak area ratio of graphite and TS-graphite was calculated using Rietveld refinement by assuming the same atomic scattering factor for each graphite measurement. The concentration ratio of graphite and TS-graphite were 67.8 and 32.2%, respectively. The analytical values of graphite were in good agreement with those of the NIST gray cast iron standard material, with concentration ratio of 53.7% and 46.3% for graphite and TS-graphite, respectively.

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Preparation and Evaluation of a Chrysotile Asbestos-containing Standard Material for Validating X-Ray Diffractometric Quantitation

Cited by 11 publications

References 21 publications

Approaches to solid sample preparation based on analytical depth for reliable X‐ray fluorescence analysis

Approaches to solid sample preparation based on analytical depth for reliable X‐ray fluorescence analysis

Crystalline Phase Quantitation of Sintered Ore with Powder X-ray Diffractometry with Rietveld Refinement

Phase Quantification of Regular and Turbo-stratified Graphite in Cast Iron by X-ray Diffractometry/Rietveld Refinement

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