THE CNESTEN EDXRF SPECTROMETERS - SENSITIVITY, CALIBRATION AND APPLICATION TO GEOCHEMISTRY (original) (raw)
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Scientia Agricola, 1994
Three certified samples of different matrices (Soil-5, SL-1/IAEA and SARM-4/SABS) were quantitatively analysed by energy dispersive X-ray fluorescence with radioisotopic excitation. The observed errors were about 10-20% for the majority of the elements and less than 10% for Fe and Zn in the Soil-5, Mn in SL-1, and Ti, Fe and Zn in SARM-4 samples. Annular radioactive sources of Fe-55 and Cd-109 were utilized for the excitation of elements while a Si(Li) semiconductor detector coupled to a multichannel emulation card inserted in a microcomputer was used for the detection of the characteristic X-rays. The fundamental parameters method was used for the determination of elemental sensitivities and the irradiator or transmission method for the correction of the absorption effect of characteristic X-rays of elements on the range of atomic number 22 to 42 (Ti to Mo) and excitation with Cd-109. For elements in the range of atomic number 13 to 23 (Al to V) the irradiator method cannot be appl...
Journal of Spectroscopy
We applied both the ordinary linear regression (OLR) and the new uncertainty weighted linear regression (UWLR) models for the calibration and comparison of a XRF machine through 59 geochemical reference materials (GRMs) and a procedure blank sample. The mean concentration and uncertainty data for the GRMs used for the calibrations (Supplementary Materials) (available here) filewere achieved from an up-to-date compilation of chemical data and their processing from well-known discordancy and significance tests. The drift-corrected XRF intensity and its uncertainty were determined from mostly duplicate pressed powder pellets. The comparison of the OLR (linear correlation coefficient r∼0.9523–0.9964 and 0.9771–0.9999, respectively, for before and after matrix correction) and UWLR models (r∼0.9772–0.9976 and 0.9970–0.9999, respectively) clearly showed that the latter with generally higher values of r is preferable for routine calibrations of analytical procedures. Both calibrations were ...
Journal of Physics: Conference Series, 2019
A pressed pellet technique was developed for quantitative analysis of elements in geological samples by portable X-ray fluorescence spectrometry (pXRF). Validation of analytical method was done using eight geological reference materials (BCR-2: basalt, COQ-1: carbonatite, GSP-2: granodiorite, JA-1: andesite, JB-2: basalt, JG-1a: granodiorite, JG-2: granite and JSy-1: Syenite). Minimum concentrations of Al, Ca, Cu, Fe, K, Mn, Pb, Rb, Si, Sr, Ti, Y, Zn and Zr in geological reference materials for pXRF detection were 6.60%, 0.50%, 19 mg/kg, 0.06%, 0.35%, 120 mg/kg, 5.36 mg/kg, 7.37 mg/kg, 1.62%, 17.92 mg/kg, 0.09%, 24.90 mg/kg, 13.60 mg/kg and 51.20 mg/kg, respectively. The accuracy of the developed method was acceptable with the mean error below 18%. The geological samples received from the Department of Mineral Resources (DMR) were also tested using this method. The results showed that the concentration values obtained by the studied method were in good agreement with those obtained ...