Conditions affecting oxide quantification in unknown tropical soils via handheld X-ray fluorescence spectrometer

Soil Research ◽  
2018 ◽  
Vol 56 (6) ◽  
pp. 648 ◽  
Author(s):  
M. L. T. Santana ◽  
B. T. Ribeiro ◽  
S. H. G. Silva ◽  
G. C. Poggere ◽  
L. R. G. Guilherme ◽  
...  
Keyword(s):  
Soil Profile ◽  
Low Cost ◽  
Tropical Soils ◽  
Soil Samples ◽  
Soil Matrix ◽  
X Ray ◽  
Plastic Bags ◽  
Colour System ◽  
Fluorescence Spectrometer

Soil chemical characterisation has been accurately performed worldwide using portable X-ray fluorescence (pXRF), contributing to fast, low-cost and environmentally-friendly soil analyses. However, many factors can influence the pXRF performance. Thus, this work was carried out to assess the oxides (SiO2, Al2O3, Fe2O3, TiO2 and P2O5) in tropical soils via pXRF, evaluating the effects of soil packing prior to analysis and the soil matrix. The packing of soil samples was performed using X-ray thin-film and common, low-cost plastic bags. Different soil matrices were obtained by grouping of samples according to the Munsell colour system. The obtained results were compared with a conventional method employed for the determination of soil oxides. In addition, the pXRF measurements made on either sieved soil samples or directly on the soil profile were compared. The P2O5 content was below the detection limit of pXRF (0.05 g kg−1). The Fe2O3 and TiO2 contents of several tropical soils were accurately determined via pXRF using air-dried and sieved samples. This result was not observed for SiO2 and Al2O3. For Fe2O3, a good correlation (R2 = 0.91) was obtained between pXRF measurements made on sieved soil samples and directly on the soil profile. The packing of soil samples using plastic bags did not negatively influence the pXRF performance.

Application of the portable spectrometer XRF for the determination of content of some metals in soil: A case study from Holy Cross Mountains (Central Poland)

2018 ◽  
Vol 472 (472) ◽  
pp. 285-302
Author(s):  
Paweł Kuć ◽  
Piotr Lenik ◽  
Jakub Bazarnik
Keyword(s):  
High Accuracy ◽  
Soil Samples ◽  
Arithmetic Means ◽  
X Ray ◽  
Holy Cross Mountains ◽  
Accuracy Of Measurements ◽  
Geochemical Studies ◽  
Fluorescence Spectrometer

The analysis of chemical composition using the portable X-ray fluorescence spectrometer (p-XRF) is recently rapidly developing instrumental research method. This method was applied to analyze the content of selected elements in soil samples from the Strużna region of the Holy Cross Mountains. The Olympus Delta Premium p-XRF spectrometer (4W Ta anode X ray tube, 40 kV, 200 μA current beam, “soil” mode, 135 seconds) was used. Prior to analyze the soil samples, the NIST 2710a and NIST 2711a reference standards were utilized in order to calibrate the p-XRF spectrometer. The maps showing obtained results of K, Ca, Fe, Mn, Cu, Zn, As and Pb were constructed using the SURFER 7.0 software with kriging procedure. The obtained results show arithmetic means similar to the previously obtained using traditional methods of chemical analysis for the soils of Holy Cross Mountains. These results combined with the high accuracy of measurements obtained by using the p-XRF Olympus Delta X spectrometer proved this device to be the effective tool for environmental and geochemical studies.

scholarly journals Multiple linear regression and random forest to predict and map soil properties using data from portable X-ray fluorescence spectrometer (pXRF)

2017 ◽  
Vol 41 (6) ◽  
pp. 648-664 ◽  
Author(s):  
Sérgio Henrique Godinho Silva ◽  
Anita Fernanda dos Santos Teixeira ◽  
Michele Duarte de Menezes ◽  
Luiz Roberto Guimarães Guilherme ◽  
Fatima Maria de Souza Moreira ◽  
...  
Keyword(s):  
Random Forest ◽  
Linear Regression ◽  
Soil Properties ◽  
Multiple Linear Regression ◽  
Low Cost ◽  
High Accuracy ◽  
Important Variable ◽  
X Ray ◽  
Element Contents ◽  
Fluorescence Spectrometer

ABSTRACT Determination of soil properties helps in the correct management of soil fertility. The portable X-ray fluorescence spectrometer (pXRF) has been recently adopted to determine total chemical element contents in soils, allowing soil property inferences. However, these studies are still scarce in Brazil and other countries. The objectives of this work were to predict soil properties using pXRF data, comparing stepwise multiple linear regression (SMLR) and random forest (RF) methods, as well as mapping and validating soil properties. 120 soil samples were collected at three depths and submitted to laboratory analyses. pXRF was used in the samples and total element contents were determined. From pXRF data, SMLR and RF were used to predict soil laboratory results, reflecting soil properties, and the models were validated. The best method was used to spatialize soil properties. Using SMLR, models had high values of R² (≥0.8), however the highest accuracy was obtained in RF modeling. Exchangeable Ca, Al, Mg, potential and effective cation exchange capacity, soil organic matter, pH, and base saturation had adequate adjustment and accurate predictions with RF. Eight out of the 10 soil properties predicted by RF using pXRF data had CaO as the most important variable helping predictions, followed by P2O5, Zn and Cr. Maps generated using RF from pXRF data had high accuracy for six soil properties, reaching R2 up to 0.83. pXRF in association with RF can be used to predict soil properties with high accuracy at low cost and time, besides providing variables aiding digital soil mapping.

Determination and Evaluation of Dead Time for X-Ray Fluorescence Spectrometer

2013 ◽  
Vol 544 ◽  
pp. 445-449
Author(s):  
Ran Yan ◽  
Yu Bing Liu ◽  
Ping Dai
Keyword(s):  
Dead Time ◽  
Practical Method ◽  
Spectral Lines ◽  
Fluorescence Detector ◽  
X Ray ◽  
Analyte Content ◽  
Pair Method ◽  
Fluorescence Spectrometer ◽  
Sample Ratio

When an X-ray photon which is generated by the sample enters into the detector, pulses can be produced and recorded. The detector is unable to respond to another photon that enters at the same time when a photon is being detected. The time that the detector takes to respond to a photon is regarded as dead time. For the x-ray fluorescence detector, the recorded count is less than the real count impulse due to dead time. Hence, to correct x-ray intensity of samples whose element content is vastly different, determination of dead time is necessary. In this paper, a new and complete way to determine dead time is proposed, which can be summarized as “intensity pair method”. Three “intensity pairs” were used for determining dead time, which were “intensity pair” of collimators (S2 and S4), “intensity pair” of spectral lines (Kα and Kβ) and “intensity pair” of beads with different flux-sample ratio (higher SH and lower SL analyte content in the beads). It comes to a conclusion that dead time obtained from “intensity pair” of beads is the most practical method for correcting X-ray fluorescence intensity. As for routine analysis, the dead time of proportional counter can be accurate to 1×10-9s, which can make intensity correction error less than 0.1%.

An integrated system for field analysis of Cd(ii) and Pb(ii) via preconcentration using nano-TiO2/cellulose paper composite and subsequent detection with a portable X-ray fluorescence spectrometer

RSC Advances ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. 9002-9006 ◽  
Author(s):  
Xiaofeng Lin ◽  
Shun-Xing Li ◽  
Feng-Ying Zheng
Keyword(s):  
Integrated System ◽  
Field Analysis ◽  
Nano Tio2 ◽  
X Ray ◽  
Cellulose Paper ◽  
Analytical System ◽  
Fluorescence Spectrometer

An integrative field analytical system was developed for the determination of Pb(ii) and Cd(ii).

Measurement of Multilayer Film Thickness Using X-Ray Fluorescence Spectrometer

2017 ◽  
Vol 726 ◽  
pp. 85-89
Author(s):  
Lei Zhang ◽  
Man Li ◽  
Hai Jian Li ◽  
Xin Song
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Multilayer Film ◽  
Rapid Determination ◽  
Middle Layer ◽  
X Ray ◽  
Fundamental Parameters ◽  
Minimum Number ◽  
Fluorescence Spectrometer

Energy dispersive X-ray fluorescence spectrometry (EDXRF) allows a rapid determination of the concentration of elemental constituents or the thickness of thin film, it has been widely used in the industry of thin film thickness. But for multilayer film, especially the middle layer, with the absorption and enhance effect of other layers, the thickness and intensity of the middle layer is not a linear relationship. This paper reports a quantitative analysis of multilayer film thicknesses based on the use of EDXRF and fundamental parameters method. The thickness of multilayer film can be easily determined with the CTCFP software because it requires a minimum number of pure elementals only. Analysis of double-layer thin films using the CTCFP software shows that the inter-element and inter-layer X-ray absorptions and enhancements in a specimen have been determined properly. Results obtained on the standards confirmed the accuracy of the method.

Determination of water content in silica nanopowder using wavelength-dispersive X-ray fluorescence spectrometer

2011 ◽  
Vol 99 (2) ◽  
pp. 332-338 ◽  
Author(s):  
Yong Suk Choi ◽  
Jong-Yun Kim ◽  
Suk Bon Yoon ◽  
Kyuseok Song ◽  
Young Jin Kim
Keyword(s):  
Water Content ◽  
X Ray ◽  
Silica Nanopowder ◽  
Fluorescence Spectrometer
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