scholarly journals Comparative Study of Three Mixing Methods in Fusion Technique for Determining Major and Minor Elements Using Wavelength Dispersive X-ray Fluorescence Spectroscopy

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5325
Author(s):  
Dan-Ping Zhang ◽  
Ding-Shuai Xue ◽  
Yan-Hong Liu ◽  
Bo Wan ◽  
Qian Guo ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Fluorescence Spectroscopy ◽  
Matrix Effects ◽  
Certified Reference Materials ◽  
Accurate Analysis ◽  
X Ray ◽  
Minor Elements ◽  
The Matrix ◽  
Sample Preparation Procedure ◽  
Coefficient Method

Accurate analysis using a simple and rapid procedure is always the most important pursuit of analytical chemists. In this study, a new sample preparation procedure, namely the shaker cup (SH) method, was designed and compared with two sample preparation procedures, commonly used in the laboratory, from three aspects: homogeneity of the sample–flux mixture, potential for sample contamination, and sample preparation time. For the three methods, a set of 54 certified reference materials (CRMs) was used to establish the calibration curves, while another set of 19 CRMs was measured to validate the results. In the calibration procedures, the matrix effects were corrected using the theoretical alpha coefficient method combined with the experimental coefficient method. The data of the major oxides (SiO2, TiO2, Al2O3, TFe2O3, MnO, MgO, CaO, Na2O, K2O, and P2O5) and minor elements (Cr, Cu, Ba, Ni, Sr, V, Zr, and Zn) obtained by wavelength dispersive X-ray fluorescence spectroscopy (WD-XRF) were compared using two derivative equations based on the findings by Laurence Whitty-Léveillé. The results revealed that the WD-XRF measured values using the SH method best agreed with the values recommended in the literature.

An Improved Sample Preparation and Analysis Technique for the Determination of Minor Elements in Catalytic Materials by Radio-Isotope Induced X-Ray Fluorescence

1980 ◽  
Vol 24 ◽  
pp. 393-398 ◽  
Author(s):  
John J. LaBrecque
Keyword(s):  
Sample Preparation ◽  
Standard Procedure ◽  
Internal Standard ◽  
X Ray ◽  
Minor Elements ◽  
Catalytic Materials ◽  
Cobalt Nickel ◽  
Analysis Technique ◽  
The Matrix

SummaryAn improved method for sample preparation and determination of minor elements in catalytic materials by radioisotope induced X-ray fluorescence is presented. The sample preparation is simple and rapid, it utilizes both and internal standard procedure as well as a thin film technique. Synthetic standards are prepared simply by mixing thoroughly the appropriate amounts of the elements of interest as their respective oxides with the matrix and the internal standard. The above standards are used to calculate the relative-fluorescence ratio factors (FJL) for each element of interest relative to the internal standard.Some of the different types of deviations (sample preparation, standard counting, instrumental, etc) will be shown for typical determinations applying experimental methods. Finally the application of this technique for the determination of Cobalt, Nickel, Molybdenum, Platinum and Palladium in catalytic materials is presented.

scholarly journals Possible Pitfalls in the Analysis of Minerals and Loose Materials by Portable XRF, and How to Overcome Them

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Valérie Laperche ◽  
Bruno Lemière
Keyword(s):  
Fluorescence Spectroscopy ◽  
Laboratory Data ◽  
Data Sets ◽  
Light Elements ◽  
Portable Xrf ◽  
X Ray ◽  
Protective Films ◽  
The Matrix ◽  
Valuable Complement ◽  
Physical Effects

Portable X-ray fluorescence spectroscopy is now widely used in almost any field of geoscience. Handheld XRF analysers are easy to use, and results are available in almost real time anywhere. However, the results do not always match laboratory analyses, and this may deter users. Rather than analytical issues, the bias often results from sample preparation differences. Instrument setup and analysis conditions need to be fully understood to avoid reporting erroneous results. The technique’s limitations must be kept in mind. We describe a number of issues and potential pitfalls observed from our experience and described in the literature. This includes the analytical mode and parameters; protective films; sample geometry and density, especially for light elements; analytical interferences between elements; physical effects of the matrix and sample condition, and more. Nevertheless, portable X-ray fluorescence spectroscopy (pXRF) results gathered with sufficient care by experienced users are both precise and reliable, if not fully accurate, and they can constitute robust data sets. Rather than being a substitute for laboratory analyses, pXRF measurements are a valuable complement to those. pXRF improves the quality and relevance of laboratory data sets.

Detection Confirmation and Determination of Trace Amounts of Selenium by X-Ray Methods

1963 ◽  
Vol 7 ◽  
pp. 542-554
Author(s):  
Frank L. Chan
Keyword(s):  
Matrix Effects ◽  
Hexagonal Structure ◽  
Elemental Selenium ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yellow Color ◽  
The Matrix ◽  
Ray Methods ◽  
Tetravalent State

AbstractRecently, interest in the determination of selenium in trace amounts has been greatly intensified because of the nutritional aspects of this element. It has been reported that selenium in the amount of 13 μg in the form of sodium selenite in 100 g of feed has an effect similar to that of vitamin E. In the field of semiconductors, the detection and determination of trace amounts of selenium in arsenic, antimony, and small single crystals of solid solution of cadmium selenide and sulfide are of considerable importance in semiconductor performance.In the Aerospace Research Laboratories, 4,5 diamino-6-tbiopyi-imidine has been successfully adopted as a reagent for the spectrophotometric determination of selenium. The reaction of 4,5 diamino-6-thiopyrimidine and tetxavalent selenium produces a yellow color with the formation of elemental selenium. It is possible to determine elemental selenium by collecting it in a thin layer. The selenium deposited in this layer may then be determined by an X-ray fluorescence method. A procedure of this nature has the advantage of eliminating the matrix effects commonly encountered in X-ray fluorescence. Furthermore, the slow generation of selenium affords a convenient means of detection and confirmation of this element by the use of X-ray diffraction procedures. By this technique selenium is first converted to its tetravalent state and is then reacted with 4,5 diamino-6-thiopyrimidine. On standing, the selenium is reduced to a red precipitate of elemental selenium which can be dissolved in carbon disulfide. Finally, the selenium can be converted into its hexagonal structure by annealing at 205-207°C.

Evaluation of Automated Sample Preparation for Mycotoxin Analysis in Foods

2020 ◽  
Vol 103 (4) ◽  
pp. 1052-1059 ◽  
Author(s):  
Kai Zhang
Keyword(s):  
Sample Preparation ◽  
Reference Materials ◽  
Certified Reference Materials ◽  
Peanut Butter ◽  
Method Performance ◽  
Robotic Arms ◽  
Automated Sample Preparation ◽  
Sample Preparation Procedure ◽  
Mycotoxin Analysis

Abstract Background In the present study, we developed a novel automated sample preparation workflow for the determination of mycotoxins in foods. Objective This workflow integrates off-line devices such as a centrifuge, shaker, liquid and solid dispensing units into a unified platform to perform gravimetric and volumetric dispensing, capping/decapping, extraction, shaking, filtration, and centrifugation. Two robotic arms provide sample transportation without human assistance. Method Critical method performance attributes were characterized using spiked corn, milk and peanut butter containing aflatoxins, deoxynivalenol, fumonisins, ochratoxin A, HT-2 and T-2 toxins and zearalenone and certified reference materials. Prepared samples were analyzed by liquid chromatography mass spectrometry (LC-MS). Results Recoveries of spiked samples range 100–120% with RSD<20% and the majority of measured values of certified reference materials are consistent with certified values within ±20%. Within- and between-batch variabilities of QC samples range 5–9% and 7–12% respectively. Conclusions Our workflow introduces a straightforward and automated sample preparation procedure for LC-MS-based multimycotoxin analysis. Further, it demonstrates how individual sample preparation devices, that are conventionally used off-line, can be integrated together. Highlights This study shows automated sample preparation will replace manual operations and significantly increase the degree of automation and standardization for sample preparation.

Minor elements in some rocks and minerals of the Rakha mines area, Singhbhum, India

1968 ◽  
Vol 36 (281) ◽  
pp. 671-675 ◽  
Author(s):  
S. B. Bhattacherjee ◽  
A. K. Ghosh ◽  
L. Bhattacherjee ◽  
Santi Bhattacherjee
Keyword(s):  
Fluorescence Spectroscopy ◽  
Shear Zone ◽  
Mica Schist ◽  
Genetic Link ◽  
X Ray ◽  
Minor Elements ◽  
Hydrothermal Origin ◽  
Sulphide Ores ◽  
Geochemical Studies ◽  
Different Parts

SummaryThe minor elements present in some rocks and minerals of the Rakha mines area, Singhbhum district, Bihar, India, have been determined by X-ray fluorescence spectroscopy. Geological and geochemical studies in different parts of this shear zone already favour a hydrothermal origin. Some of the minor elements concentrated in the sulphide ores are found in lower concentration in the epidiorite and the chlorite-mica schist; these are, however, present in abundance in the soda-granites that are closely associated in space to the east and west of the Rakha mines area. A genetic link between sulphide ores and soda-granite may be predicted although the sulphides in the Rakha mines area are not directly associated with the soda-granite.

Comparison of Three Sample Preparation Techniques for Determination of Organic Bromide and Chloride in Halogenated Lipids by X-Ray Fluorescence Spectroscopy

1980 ◽  
Vol 63 (4) ◽  
pp. 709-712
Author(s):  
Henry B S Conacher ◽  
Rajinder K Chadha ◽  
Gladys Lacroix
Keyword(s):  
Thin Film ◽  
Sample Preparation ◽  
Fluorescence Spectroscopy ◽  
Vegetable Oils ◽  
X Ray ◽  
Thin Film Technique ◽  
High Concentrations ◽  
Preparation Techniques

Abstract Three sample preparation techniques—thin-film, solution, and cellulose pellet—were applied to the determination of bromide in brominated lipids by X-ray fluorescence spectroscopy. Using brominated vegetable oils of known bromide content it was demonstrated that the thin-film technique could result in erroneously high bromide contents, which could also vary with the amount of oil applied, depending on the solvent used. As solutions in hexane, slightly high bromide contents were observed at high concentrations. With the cellulose pellets, bromide contents similar to known values were observed. It was concluded that the cellulose pellet procedure, although more time consuming, and less convenient for ready recovery of sample, was the most suitable for organic bromide determination. Similar results were indicated for chlorinated oils.

Backscatter/Fundamental-Parameters Analysis of Unweighed Samples using Multi-Target, Multi-Crystal Regions of Interest from WDXRF and EDXRF

1991 ◽  
Vol 35 (B) ◽  
pp. 1101-1106
Author(s):  
Richard J. Arthur ◽  
Ronald W. Sanders
Keyword(s):  
Matrix Effects ◽  
Computer Code ◽  
Total Sample ◽  
Regions Of Interest ◽  
Energy Dispersive ◽  
Fundamental Parameter ◽  
Accurate Analysis ◽  
X Ray ◽  
Fundamental Parameters ◽  
Target Energy

AbstractA method has been developed to simultaneously compute matrix corrections from a composite spectrum of multi-target energy-dispersive (EDXRF) and multicrystal wavelength—dispersive (WDXRF) x-ray fluorescence systems, A serial line installed between the WDXRF and EDXRF spectrometers via a PDF 11/34a computer allows acquired wavelength data to be digitally transformed into an energy spectrum. The low-energy x-ray information from the WDXRF unit is then coupled with the backscatter coherent/incoherent information from the EDXRF unit, enabling enhanced quantitative analysis for low-atomic-number (low-Z) elements. The peak resolution obtainable from the WDXRF spectra often removes the necessity for peak-overlap corrections.Backscatter intensities obtained from the EDXRF unit are used to provide information on total sample mass and to correct for matrix effects. The resulting backscatter fundamental-parameter (BFP) calculations generally provide an accurate analysis of samples without prior knowledge of the sample matrix. Such an approach is particularly useful for samples in which quantities of carbon, oxygen, and other low-Z constituents cannot be explicitly determined.Regions of interest (ROI) are created by the computer code “PREP” and processed by the BFP code "MSAP" an extension of the “SAP3” computer program for quantitative multielement analysis by energy-dispersive x-ray fluorescence,

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