X-ray fundamental parameter methods for the determination of some elements in hydrocarbons by WDXRF

1993 ◽  
Vol 347 (3-4) ◽  
pp. 111-113 ◽  
Author(s):  
Antoni Marchut
Keyword(s):  
Fundamental Parameter ◽  
X Ray

Determination of the crystal structure of magnesium perchlorate hydrates by X-ray powder diffraction and the charge-flipping method

2010 ◽  
Vol 66 (6) ◽  
pp. 579-584 ◽  
Author(s):  
Kevin Robertson ◽  
David Bish
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Fundamental Parameter ◽  
Magnesium Perchlorate ◽  
Space Group ◽  
X Ray ◽  
Partial Pressures ◽  
Dehydration Reactions

X-ray powder diffraction (XRD) data were used to solve the crystal structures of phases in the magnesium perchlorate hydrate system, Mg(ClO4)2·nH2O (n = 4, 2). A heating stage and humidity generator interfaced to an environmental cell enabled in-situ XRD analyses of dehydration reactions under controlled temperatures and partial pressures of H2O (P_{{\rm H}_2{\rm O}}). The crystal structures were determined using an ab initio charge-flipping method and were refined using fundamental-parameter Rietveld methods. Dehydration of magnesium perchlorate hexahydrate to tetrahydrate (348 K) results in a decrease in symmetry (space group = C2), where isolated Mg2+ cations are equatorially coordinated by four H2O molecules with two [ClO4]− tetrahedra at the apices. Further dehydration to the dihydrate (423 K) leads to bridging of the isolated packets to form double corner-sharing chains of octahedra and polyhedra (space group = C2/m).

Quantitative Trace Analysis by X-ray Fluorescence Using the Computer Program NRLXRF

1982 ◽  
Vol 36 (1) ◽  
pp. 19-22 ◽  
Author(s):  
J. A. Keenan ◽  
D. Holmes
Keyword(s):  
Aluminum Alloys ◽  
Computer Program ◽  
Standard Reference Materials ◽  
Parameter Method ◽  
Fundamental Parameter ◽  
National Bureau ◽  
X Ray ◽  
Trace Constituents ◽  
Fundamental Parameter Method

The computer program NRLXRF has been applied to the determination of minor and trace constituents in aluminum alloys and several National Bureau of Standards certified standard reference materials. Limitations arising from energy dispersive x-ray analysis and the fundamental-parameter method used by NRLXRF are illustrated.

Advances in Fundamental-Parameter Methods for Quantitative XRFA

1986 ◽  
Vol 30 ◽  
pp. 97-104 ◽  
Author(s):  
Michael Mantler
Keyword(s):  
Quantitative Analysis ◽  
Single Layer ◽  
Precise Determination ◽  
Emission Lines ◽  
Fundamental Parameter ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Intensity Ratios ◽  
Specimen Shape

The fundamental-parameter technique is an important tool for quantitative x-ray chemical analysis and is routinely applied for the quantification of bulk specimens and single layer films. A method extending it to multiple film layers has recently been introduced by Mantler and results from such applications have been reported by Huang and Parrish. In addition, fundamental-parameter methods can be employed to predict intensity ratios of fluorescent lines as well as the spectral distribution of radiation scattered by the specimen (shape of the background in the vicinity of emission, lines). This is useful for accurate quantitative analysis in the case of a poor peak-to-background ratio, where the precise determination of net intensities is difficult.

Analysis of Lead in SnAg Based Solders Using X-Ray Fluorescence

2013 ◽  
Vol 752 ◽  
pp. 37-41
Author(s):  
Dániel Koncz-Horváth ◽  
Zoltán Gácsi
Keyword(s):  
Fundamental Parameter ◽  
Parameter Calibration ◽  
Solder Alloys ◽  
Production Lines ◽  
Screening Analysis ◽  
X Ray ◽  
Low Level ◽  
Empirical Calibration ◽  
Calibration Methods

This paper reports the results of ED-XRF method for the determination of low-level contaminated solders. The method was calibrated for the analysis of part-per-million (ppm) levels of Pb and major levels of other elements. In this work, two types of Sn-Ag based solder alloys are used; the ternary Sn-3.0wt%Ag-0.5wt%Cu (SAC305) and the 6-part Sn-3.5wt%Ag-3.2wt%Bi-1.6wt%Sb-0.5wt%Cu-0.15wt%Ni were examined. Empirical calibration and fundamental parameter calibration were used to analyze samples. The results of this study demonstrate the differences between the applied calibration methods for detection of Pb. Screening analysis of bulk samples from variant production lines were also discussed.

EDXRF Determination of Major and Minor Elements in Compound Fertilizers

1984 ◽  
Vol 28 ◽  
pp. 215-220
Author(s):  
Leif Højslet Christensen ◽  
Leif Rasmussen
Keyword(s):  
Sample Preparation ◽  
Unique Solution ◽  
Fundamental Parameter ◽  
Fluorescence Technique ◽  
Matrix Correction ◽  
X Ray ◽  
Minor Elements ◽  
Elemental Analyses ◽  
Precision And Accuracy

AbstractThe combination of the energy-dispersive x-ray fluorescence technique and a backscatter/fundamental parameter-based matrix correction approach provides a new and unique solution to elemental analyses of fertilizers. This is demonstrated by means of results obtained for three reference materials and a range of in-house fertilizers. The results further demonstrate problems of sample preparation as well as the precision and accuracy of the method.

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