Energy Dispersive X-ray Fluorescence Equipment Research Articles

Optimization of pXRF instrumentation conditions and multivariate modeling in soil fertility attributes determination

The increasing global demand for agricultural products, food, and energy requires a sustainable and secure approach to agricultural production. Soil nutrition is vital for enhancing agricultural productivity, and understanding the spatial variability of fertility attributes is crucial in soil fertility prevention. Traditional soil analysis methods are time-consuming, costly, and generate waste. Spectral-analytical techniques, such as energy dispersive X-ray fluorescence (EDXRF) combined with multivariate analysis, offer a faster, cost-effective, and environmentally friendly alternative. This study aimed to optimize measurement conditions for predicting soil fertility attributes using a commercial routine from a portable EDXRF (pXRF) equipment and compare its performance with benchtop EDXRF using Partial Least Squares Regression (PLS) modeling. The data fusion from different measurement conditions using low- and mid-level fusion approaches was explored to evaluate the models' synergy. 364 soil samples at three different depths were used. The study area covers 12 ha of Red Latosol and Red Nitosol. Ten fertility attributes were evaluated: exchangeable macronutrients (Ca2+, Mg2+, and K+), available phosphorus (PM), pH, potential acidity (H + Al), soil organic carbon (SOC), cation exchange capacity (CEC), sum of exchange bases (SB) and base saturation percentage (BSP). The results indicated that the measurement of the three experimental conditions tested is unnecessary, and the data fusion does not significantly improve the model's performance. The use of 15 kV and 12.15 μA without filters provided the best performance results for all attributes simultaneously. By the established RPD ranges, the SOC, CEC, SB, and Ca2+ models were considered very good for quantitative prediction (RPD >2.0), while the K+ and Mg2+ models were considered good for quantitative predictions (1.8 < RPD < 2.0). The PM, pH, BSP, and H + Al models provided fair predictions, which may be used for evaluation and correlation (RPD <1.8). Furthermore, the pXRF optimized condition provided results equivalent to those modeled with benchtop EDXRF data. These results highlight the potential of pXRF as an economical, rapid, and efficient alternative approach to the conventional method, and may provide valuable insight for decision-making related to the use of fertilizers and other soil correction products.

Portable EDXRF spectrometer: determination of linearity, LOD, LOQ, and working range for the analysis of base and precious metals in liquid matrices

Utilizing a portable energy dispersive X-ray fluorescence (EDXRF) spectrometer and certified reference materials, this study aimed to determine the linearity, limit of detection (LOD), limit of quantification (LOQ), and working range of the method for quantitative analysis of base and precious metals in liquid matrices. As the EDXRF method lacks standardization and is highly susceptible to matrix effects, these calculations play a crucial role in the analytical validation process. The obtained R2 values in this study exceeded 0.99, and the residuals exhibited a random distribution pattern. The LOD and LOQ values were determined to be exceptionally low, approaching the resolution limit of the spectrometer. Consequently, our calculations confirmed the analytical validation of the portable EDXRF method for analyzing elements in liquid matrices. The utilization of portable EDXRF equipment in quantitative measurements of elements in liquid matrices represents an innovative approach, unveiling new areas of application for this type of instrument.

Direct determination by portable ED-XRF of mineral profile in cocoa powder samples.

The present study has exploited the rapidity of the analysis and the multi-elemental capability of the energy dispersive X- ray fluorescence (ED-XRF) technique for the mineral profile determination in cocoa powder. A fast, cheap and environmental sustainable method without reagent consumption or toxic waste generation has been proposed. The samples can be prepared in the form of pellets of 13 mm in diameter and 2-3 mm thickness. The different internal calibrations used by ED-XRF equipment did not provide accurate results when comparing the mineral profile with the concentration obtained by Inductively Couple Plasma Optical Emission Spectroscopy (ICP-OES) after microwave assisted digestion of samples. For direct ED-XRF analysis of the cocoa samples, an external calibration using as standards the cocoa samples diluted with sugar was prepared. The analytical parameters of Relative Standard Deviation and Limit of Detection for the determined elements are adequate to the concentration levels found in the samples.

Análise Multielementar de solos: uma proposta envolvendo equipamento portátil de fluorescência de raios X

Portable instruments are excellent choices to perform precision agriculture since they allow in situ information about soil composition. In such a way, results are obtained quickly and inputs can be applied promptly, depending on the local soil characteristics. This study aims to develop a method to measure inorganic elements at in natura soils using a portable EDXRF (Energy Dispersive X-ray Fluorescence) equipment and multivariate calibration through Partial Least Square Regression (PLS). Seven certified reference standards are used to build the PLS models for Si, K, Ca, Mn and Fe. Two standards are separated for external PLS validation. Finally, the results show that a maximum of 21% is obtained for relative deviation.

Portable energy-dispersive X-ray fluorescence equipment for the analysis of cultural heritage

Energy-dispersive X-ray fluorescence (EDXRF) especially in its portable version, generally characterized by a small X-ray tube and a Si-PIN or Si-drift detector is particularly useful to analyse works of art. EDXRF technique is nondestructive, noninvasive and multielemental. A variety of works, such as paintings of all types (including frescos and illuminated manuscripts), bronzes and brasses, gold alloys, silver alloys, ceramics, porcelains and faiences, papers, ink, stones of all types (marbles, obsidians etc.), stamps, etc. can be studied using a portable EDXRF equipment. In this paper, examples are given for analysis of the works of art with a portable EDXRF equipment.

Energy dispersive X-ray fluorescence analysis of ancient coins: The case of Greek silver drachmae from the Emporion site in Spain

Greek colonizers arrived at the Iberian Peninsula at the beginning of the sixth century B.C. and founded a small colony known as Emporion in north-east Spain. By the fifth century B.C., this colony became a small polis with a well-organized administrative structure. In this context, the necessity of coinage was a fact and the first coins were minted [1]. Some of these coins were characterized by using energy dispersive X-ray fluorescence equipment. The analytical study focused on the elemental characterization of the coins minted from the fourth century to the first century B.C. and their compositional evolution during this period. The investigation has pointed out a very high fineness of the alloys throughout the time, with an average silver content around 98.32%, and the feasibility of energy dispersive X-ray fluorescence as a screening tool for the characterization of the alloys.

From Giotto to De Chirico to Verrocchio: analyses of paintings and historical bronze alloys availing of portable EDXRF equipment

Energy-dispersive X-ray fluorescence (EDXRF) has been used successfully for some time now in non-destructive diagnostic examinations of art works, especially for paintings and bronze works. Furthermore, such examinations may be carried out with portable equipment, allowing studies in situ. EDXRF-analysis of paintings generally provides the following information: –possible presence of elements on the surface (sulphur, chlorine) due to pollution; –identification of the elements, and therefore giving a good indication of the pigments, employed by the artist; and –identification of previous restoration areas, by detecting the presence of “modern” elements, such as titanium, zinc, cadmium, etc. Recently, the famous Chapel of the Scrovegni painted by Giotto in Padua in 1303–1305 was analysed in detail to obtain all the information described above. Another example of application of EDXRF-analysis to paintings was a recent examination of 11 paintings believed to be by De Chirico the outcome of which was compared ...

Areas and limits of employment of portable EDXRF equipment for in situ investigations

The use of mobile spectrometers in the archaeometric study of ancient artefacts has become a very common practice over the past few years. It docs open methodological questions on the employment of such techniques in a non-destructive manner, i.e. avoiding the damage of the artifact. Some additional methodological questions come by (i) the use of such instrumentation for diagnostic scopes (in which a different approach to the measurement is required) and (ii) the use of the spectrometers in systematic analysis on big number of artefacts, stored in several museums (during experimental campaigns). This paper's aim is to discuss some of this questions, on the basis of the experience in the use of mobile (or Field Portable) systems for Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopy that we have harvested in the last years. Our conclusions mainly regard the precision of measures, which is related both to the positioning of the spectrometer and to the instrument's instability. Also we deal with the more complex problem of the object's matrix not being homogeneous and of how this can affect the response of the measuring system. Moreover, it is discussed the more general question of the use of portable spectrometers and, consequently, of the meaning one can give to the results so obtained. As a matter of fact the use of such systems, which have an intrinsic analytic potential, in a non-destructive manner, frequently creates ambiguities that have not been, sometimes, taken into account with attention by the investigators. Finally some ideas arc traced on the development of methodologies which favor a better use of such spectroscopic systems for the analysis of ancient artefacts.

Comparison of total-reflection X-ray fluorescence, static and portable energy dispersive X-ray fluorescence spectrometers for art and archeometry studies

Abstract In this paper, a Total-reflection X-ray Fluorescence (TXRF), a static and a portable Energy Dispersive X-ray Fluorescence (EDXRF) spectrometers are described. Both the equipments and the techniques employed in the field of the art and archeometry are compared. Some applications in this area are presented as well. The aim of the work is to know which spectrometer is the best suited depending on the work of art and the problem treated. The conclusion reached from the experience is that the portable EDXRF spectrometer is advisable to make “in situ” and online analysis in a multidisciplinary environment, the static EDXRF equipment is good to perform analysis on paper and metal pieces and the TXRF spectrometry is the best technique for very sensitive analysis of trace elements from micro-samples. Within the last technique, we propose to analyze the cottons used by the restorers in the different steps of the restoration process since it could be a good tool to study the composition of different layers and zones of the work of art.

Geochemical multi-element prospecting for carbonatites by energy-dispersive x-ray fluorescence

A radionuclide-excited energy-dispersive X-ray fluorescence (EDXRF) device has been used for geochemical mapping of soils over the Orberg deposit of the Kaiserstuhl carbonatite near Schelingen. About 500 samples were collected from an area of 0.2 km 2. The mobile EDXRF equipment was used in field laboratories to determine twelve trace elements (Cu, Zn, As, Rb, Sr, Y, Zr, Nb, Ba, La, Ce and Pb) quantitatively, and the major components K 2O, CaO, TiO 2, MnO and Fe 2O 3 semiquantitatively. Additional information on bulk chemistry was obtained by determining the average atomic number from scattered radiation. An attempt is made to identify the different carbonatite subcrops in this area by use of trace element patterns and inter-element relationships. Since part of the survey area is covered with loess, relations and ratios between elements were used to estimate the dilution effect due to loess.