An improved interference correction for trace element analysis

Author(s):  
John J. Donovan ◽  
Donald A. Snyder ◽  
Mark L. Rivers

We present a simple expression for the quantitative treatment of interference corrections in x-ray analysis. WDS electron probe analysis of standard reference materials illustrate the success of the technique.For the analytical line of wavelength λ of any element A which lies near or on any characteristic line of another element B, the observed x-ray counts at We use to denote x-ray counts excited by element i in matrix j (u=unknown; s=analytical standard; ŝ=interference standard) at the wavelength of the analytical line of A, λA (Fig. 1). Quantitative analysis of A requires an accurate estimate of These counts can be estimated from the ZAF calculated concentration of B in the unknown C,Bu measured counts at λA in an interference standard of known concentration of B (and containing no A), and ZAF correction parameters for the matrices of both the unknown and the interference standard at It can be shown that:

1973 ◽  
Vol 17 ◽  
pp. 1-15
Author(s):  
H. Thomas Yolken

AbstractA review of the procedures and efforts at the National Bureau of Standards (NBS) to provide for meaningful measurements through the use of Standard Reference Materials (SRM's) is presented.The examples of NBS Standardization efforts for x-ray analysis range from basic metrology to applied environmental measurements. These examples include a determination of x-ray wavelength by a method which in part utilizes simultaneous x-ray and optical interferometry measurements of the atomic planes of near perfect silicon. In addition, Standard Reference Materials (SRM's) are being developed and applied to trace element analysis using x-ray fluorescence techniques. These efforts include development of SRM's for trace element analysis of air particulates. In another area, work is proceeding on the development of a silicon powder Standard Reference Material intended for x-ray diffractometer calibration. An effort to develop a suitable x-ray diffraction technique to determine the amount of quartz in mine dust is also underway. NBS efforts to provide SRM's for the calibration of electron microprobes and the validating of correction factor calculations are also described.


1995 ◽  
Vol 39 ◽  
pp. 109-117
Author(s):  
Burkhard Beckhoff ◽  
Birgit Kanngießer

X-ray focusing based on Bragg reflection at curved crystals allows collection of a large solid angle of incident radiation, monochromatization of this radiation, and condensation of the beam reflected at the crystal into a small spatial cross-section in a pre-selected focal plane. Thus, for the Bragg reflected radiation, one can achieve higher intensities than for the radiation passing directly to the same small area in the focal plane. In that case one can profit considerably from X-ray focusing in an EDXRF arrangement. The 00 2 reflection at Highly Oriented Pyrolytic Graphite (HOPG) crystals offers a very high intensity of the Bragg reflected beam for a wide range of photon energies. Furthermore, curvature radii smaller than 10 mm can be achieved for HOPG crystals ensuring efficient X-ray focusing in EDXRF applications. For the trace analysis of very small amounts of specimen material deposited on small areas of thin-filter backings, HOPG based X-ray focusing may be used to achieve a very high intensity of monochromatic excitation radiation.


1976 ◽  
Vol 279 (2) ◽  
pp. 160-160 ◽  
Author(s):  
R. Zeisler ◽  
J. Cross ◽  
E. A. Schweikert

2017 ◽  
Vol 27 (03n04) ◽  
pp. 125-133
Author(s):  
S. Murao ◽  
K. Sera ◽  
S. Goto ◽  
C. Takahashi ◽  
L. Cartier ◽  
...  

Recent rise of social attention towards ethical jewelry has led scientists to a challenge of how to construct analytical systems that can deliver in line with social and supply chain expectations. Of the various kinds of methods, “Proton/Particle-Induced X-ray Emission” (PIXE) seems to be robust and promising in characterizing gemstones because of its capability of trace element analysis without destruction. The authors established a non-standard method to analyze cultured pearls and applied it to test specimens from different places. The results showed that PIXE could detect important elements for pearl study with good accuracy and sensitivity and that pearl chemistry can be useful to differentiate freshwater and marine pearl products.


1988 ◽  
Vol 42 (7) ◽  
pp. 1250-1253 ◽  
Author(s):  
C. T. Yap

The method of total reflection fluorescence analysis was used to obtain concentrations of iron, copper, zinc, and bromine in human sera. It was first applied to the commercial control-serum preparation known as Seronorm, and the results obtained were in good agreement with quoted values. The method was then used to determine the concentrations of iron, copper, zinc, and bromine in a random sampling of 62 individuals in an essentially Chinese population. The results are discussed. We feel that this is a suitable method for trace-element analysis of blood in an average laboratory. It is rapid, simple, and economical, besides being multielemental and nondestructive and requiring very small quantities—which seems to be a must in pediatrics.


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