ABSTRACT The present study evaluated the applicability of Portable X‐ray Fluorescence (pXRF) for rapid determination of seed mineral concentrations in cowpea [ Vigna unguiculata (L.) Walp.] by comparing pXRF measurements with those obtained using Atomic Absorption Spectroscopy (AAS). Fifty‐seven cowpea genotypes, including two check varieties, were analysed for iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), potassium (K), and calcium (Ca). Simple linear regression was used to assess the relationship between pXRF‐ and AAS‐derived mineral concentrations using training ( n = 47) and independent validation ( n = 10) datasets. The pXRF measurements showed good agreement with the corresponding AAS values for both macro‐ and micronutrients, with comparatively stronger relationships observed for Fe, Zn, Mn, and Cu. Residual and normal Q–Q plot analyses supported the suitability of the regression models. The findings demonstrate that pXRF enables rapid, simultaneous multielement analysis with minimal sample preparation and provides an efficient approach for high‐throughput mineral phenotyping and biofortification‐oriented cowpea breeding programmes.
ABSTRACT X‐ray fluorescence (XRF) spectrometry has been an important tool in agricultural studies recently. This technique allows the multielemental, direct, and in situ analysis. The objective of this review is to evaluate the use of XRF in agriculture focusing on plant and soil samples based on indexed articles in the Scopus database from 2020 to 2024. Particularly, the review evaluated the hardware XRF set‐up (portable XRF, benchtop, and micro‐XRF), the analysis site, and instrumental operational conditions (measurement time (s), filter, atmosphere (air, vacuum, and He)), X‐ray tube voltage (kV) and current (μA), and detector. We highlight the major use of the pXRF for both matrices. The laboratory is the prevailing analysis site, even for the pXRF application. A worrisome finding from this review was the lack of proper description of the instrumental operational conditions, observed in 26% to 78% of the studies verified, considering the above‐mentioned parameters for plant and soil matrices. In short, this review unfolds the increasing use of XRF and features of its set‐up and analysis configuration in agriculture. In addition, it also alerts to the improper description of the operational conditions, as well as discusses opportunities, challenges, and future perspectives for advancing XRF applications in agriculture from the hardware standpoint.
The authentication of tobacco products by geographical origin is crucial for combating counterfeiting, especially for high-value products such as Cuban Premium cigars. This study presents a simplified method to identify the cultivation zone of tobacco leaves using energy dispersive X-ray fluorescence (EDXRF) spectra combined with multivariate statistical analysis, without prior determination of elemental concentrations. Tobacco leaves from three Cuban cultivation zones were analyzed by EDXRF. From the original 17 spectral variables, nine (S, K, Zn, WL, SrK, BrL, Cl, Ca, Mn) were retained following rigorous selection criteria. Principal component analysis (PCA) on these nine variables yielded a two-component model explaining 68% of the total variance, with all samples within 95% confidence limits. MANOVA confirmed that cultivation zone significantly affects the spectral variables. A linear discriminant analysis (LDA) model was built on 28 training samples and validated internally (leave-one-out cross-validation) and externally on six independent samples collected at different times by different operators; the LDA model achieved 100% classification accuracy on both validation sets. When applied to 11 additional samples of unknown origin (due to a labeling error), the LDA model provided zone assignments. Comparison with unsupervised PCA clustering showed 73% coincidence between the two independent methods, providing internal consistency evidence. Two principal achievements are highlighted. First, the method successfully discriminates intra-national cultivation zones using direct EDXRF spectra, offering a rapid, non-laborious, and cost-effective screening tool to combat counterfeiting of Cuban tobacco products. Second, because inter-country variability in pedoclimatic conditions and agronomic practices is expected to be substantially larger than the intra-national differences resolved here, this approach is highly promising for further development into an inter-national tobacco authentication method. The scalability of this strategy opens the door to global origin verification using simple, widely available EDXRF instrumentation.
ABSTRACT X‐ray‐based cancer therapies, including conventional radiotherapy (RT) and emerging radiodynamic therapy, are constrained by challenges such as insufficient tumor‐specific radiation absorption, collateral damage to healthy tissues, hypoxia‐induced resistance, and limited efficacy against metastatic tumors. Recent advances in nanomedicine offer versatile strategies to overcome these limitations. High atomic number (high‐Z) nanomaterials serve as radiosensitizers, enhancing x‐ray energy deposition at tumor sites while enabling precise imaging‐guided treatment. Importantly, x‐ray spectrometric techniques, including x‐ray fluorescence spectroscopy, x‐ray photoelectron spectroscopy, and x‐ray absorption spectroscopy, play a critical role in this field by enabling quantitative characterization of nanoparticle composition, surface chemistry, electronic structure, and in vivo biodistribution, supporting the optimization of energy‐dependent attenuation, dose enhancement, and nanoparticle–tissue interactions. Multifunctional nanocarriers facilitate combination therapies, integrating RT with chemotherapy, photodynamic therapy, photothermal therapy, and immunotherapy to induce synergistic anticancer effects. Modulating the tumor microenvironment through oxygen delivery, in situ oxygen generation, glutathione depletion, and peroxide decomposition amplifies ROS production, promoting DNA damage and inhibiting repair mechanisms. Radioprotective nanomaterials selectively shield normal tissues from oxidative damage, allowing the safe use of higher radiation doses. Radiodynamic therapy (RDT) employs x‐ray‐activated fluorescence to trigger photosensitizers or uses single‐component nanomaterials to generate ROS, offering deeper tissue penetration and lower radiation doses than conventional RT. Despite promising preclinical outcomes, clinical translation remains challenging due to nanomaterial biocompatibility, heterogeneous tumor distribution, photon energy dependence, and long‐term safety. Continued integration of x‐ray spectrometry with nanomaterial design, imaging‐guided therapy, and immunomodulatory approaches is expected to advance precision radiotherapy and improve clinical outcomes.
ABSTRACT The river sands from the Sakawa River Basin, Kanagawa Prefecture, Japan were characterized by X‐ray diffraction (XRD) and X‐ray fluorescence (XRF) analyses. The river sand samples were subjected to heavy‐liquid separation using a sodium polytungstate solution to separate heavy and light minerals for XRD analysis. In addition, the river sand samples and the mineral samples were melted with lithium tetraborate to prepare glass beads for XRF analysis. Five types of heavy minerals—hornblende, epidote, olivine, augite, and hypersthene—were identified in the XRD patterns of the river sand samples, and four types of river sands were differentiated based on heavy‐mineral assemblages. The composition of plagioclase, that is, the anorthite (An) mole percent content, in the river sand samples was determined using XRD and XRF. The composition of plagioclase in the river sands ranged from An 41 mol% to An 86 mol%, and two river sands with similar heavy‐mineral assemblages were differentiated by their plagioclase composition. A principal component analysis (PCA) was performed using the concentrations of 10 major elements (Na, Mg, Al, Si, P, K, Ca, Ti, Mn, and Fe) obtained by XRF. Based on the results of PCA, the two river sands with similar heavy‐mineral assemblages and plagioclase compositions were differentiated. In this study, we differentiated eight river sand samples collected from the Sakawa River Basin based on (1) heavy‐mineral assemblage, (2) plagioclase composition, and (3) PCA.
It is possible to obtain the Li Kα spectrum of LiF on an electron microprobe, with minimal damage, provided a low acceleration energy (1 kV) and a small current density (1 pA/μm 2 ) are used. The presented spectrum agrees with the one obtained with synchrotron radiation many years ago and is expected to be free of damage. The spectrum displays two main peaks: the first one at c.a . 47 eV coming from the electron transition from the occupied valence states toward the Li 1s core level; the second one at c.a . 62 eV giving evidence of the radiative recombination of the lithium core exciton. These features, as well as the background due to cathodoluminescence, change drastically after 1 min of electron irradiation, due to fluorine leaving the sample and the subsequent oxidation of the remaining lithium atoms in the residual atmosphere of the microprobe.
Lithium metal is studied in an electron probe microanalyzer equipped with a high‐resolution spectrometer working in the 40–120 eV spectral range. The sample is prepared in a nitrogen atmosphere. Metal and oxide components are observed in the Li K spectrum and the change of their relative intensity as a function of the analyzed thickness demonstrates the slight superficial oxidation of the sample. On the other hand, by applying the electron beam a long time at the same position, reduction of the sample is observed.
The present research integrates microcomputed tomography (micro‐CT), x‐ray fluorescence, and gamma‐ray transmission to quantitatively characterize wood species. A total of 22 samples from seven species were analyzed for density ( ρ ), linear attenuation coefficient ( μ ), Compton scattering, micro‐CT gray values (GV), porosity, mass attenuation coefficient ( μ m ), and the Compton–Rayleigh ratio ( R / C ). Strong linear correlations were observed between density and μ ( R 2 = 0.990), density and Compton scattering ( R 2 = 0.969), and density and GV ( R 2 = 0.993), with Pearson coefficients ranging from −0.996 to −0.982 and from 0.974 to 0.995. Principal component analysis (PCA) reduced the seven variables into two components, which accounted for 86.56% of the variance, and successfully clustered the species into three groups based on their density, porosity, and attenuation characteristics. These findings underscore the potential of integrated spectrometric and imaging techniques for nondestructive wood differentiation, offering significant benefits for cultural heritage preservation.
Following the installation of the Laboratory for the Characterization and Speciation of Aerosols (LCEA) in 2008, and the confirmation of High Resolution Energy Dispersive Spectrometry (HiREDS) as a much promising development for X‐ray Emission Spectrometry in general and Particle Induced X‐ray Emission (PIXE) in particular, the installation of the X‐ray Advanced HiREDS Research and Metrology Laboratory (XAHRM‐Lab) was launched in 2020 at the Campus Tecnológico e Nuclear (CTN) of IST, the University of Lisbon Engineering School, under the scope of the AHEAD2020 EU infrastructures project. Being a major upgrade to the LCEA, XAHRM‐Lab aims at being an ion beam analysis infrastructure focused mostly on new developments and metrology work. XAHRM‐Lab is designed to hold two X‐ray detectors to be used in six different analytical geometries, including PIXE induced XRF (πXRF) and in air geometry variants. In this work, XAHRM‐Lab installation status and a set of first results from πXRF and PIXE spectra of UFe 4 Al 8 and UFe 10 Si 2 crystals, taken without breaking vacuum, are presented and discussed.
Spectrometry is an important tool for the characterization of X-ray beams in ionizing radiation metrology. However, the use of solid-state spectrometers for accurate measurements requires correction of spectral distortions caused by the interaction between photons and the detector. In this sense, the Stripping methodology was used to correct these distortions and validate the method for the ISO 4037-1 narrow spectra series, from qualities N10 to N150, measured with an Amptek CdTe spectrometer. This method was implemented in Python 3, and its performance was evaluated quantitatively through the ISO mean energy and spectral resolution requirements, and qualitatively through the spectral shape. Monte Carlo simulations of the pulse-height distribution were performed for the N120 and N150 spectra using EGSnrc to investigate the influence of the manufacturer's collimator on the measurements. It was observed that the differences between the quantitative parameters of the corrected spectra are within the standard tolerance, except for N120 and N150, for which the shape, mean energy, and spectral resolution are significantly different, with errors of 5% and 9%, and 11% and 22%, respectively. These results suggest that the Stripping method reduces spectral distortion and is therefore suitable for correcting N10-N100 radiation qualities with a CdTe spectrometer. The divergences found for N120 and N150 are therefore related to the manufacturer's collimator, since its thickness does not properly shield these beams. New studies should therefore be conducted to develop an improved design, as suggested by the simulations.
Micro-scale X-ray fluorescence (mu XRF) is a versatile tool for non-destructive elemental quantification across materials science, environmental monitoring, and industrial analysis. Nevertheless, quantitative robustness can deteriorate under short acquisition times due to limited photon statistics, geometric instability, and absorption effects. A physically grounded strategy that enhances quantitative robustness without prolonging acquisition time is therefore highly desirable. Here, we systematically investigate a film-assisted sample configuration in a microscope-type XRF (XGT) system, focusing on acquisition time (100 s vs. 400 s) and supporting film thickness (0.1-0.3 mm) as adjustable analytical parameters. Using NaCl and DOPC-derived phosphorus as model systems, detection success rates and concentration distributions were statistically evaluated. Under photon-limited conditions (100 s), the supporting film significantly improved Na detection success rate (p < 0.05) and reduced dispersion for low-fluorescence-yield phosphorus signals (p < 0.01). Thickness-dependent effects were element-specific and persisted for phosphorus even at extended acquisition time. The observed trends reflect the combined influence of Beer-Lambert attenuation and counting statistics, demonstrating that absorption alone cannot explain the experimental behavior; mechanical stabilization and signal detection success rate jointly determine quantitative stability. These findings demonstrate that supporting film thickness should be regarded as an active optimization parameter in mu XRF rather than a passive structural component. The proposed approach enables acquisition time reduction while preserving quantitative precision and provides broadly applicable guidance for enhancing robustness in rapid micro-scale XRF analysis.
Higher order diffraction from surface contamination poses a major challenge for soft x-ray spectral analysis using reflection zone plate spectrometers in electron probe microanalysis. We developed two correction methods applied to the Al L2,3 and Zn M2,3 emissions in AlZn60 alloy spectra: sequential overlay and subtraction of C K alpha and O K alpha reference spectra, and subtraction of O K alpha higher order contributions using an isolated peak of the sample under study. The second subtraction method provides superior correction of oxygen interferences while preserving intrinsic emission shapes. These approaches were validated on the Si L and Al L bands of the leuchtenbergite mineral.
The temperature-dependent Debye-Waller (DW) factor in extended X-ray absorption fine structure (EXAFS) for gold (Au) is investigated by explicitly accounting for thermal disorder effects. The theoretical model is constructed by combining classical statistical theory with the correlated Einstein model and the anharmonic effective potential to describe correlated local Au-Au vibrations. Within this framework, analytical closed-form expressions for thermodynamic EXAFS parameters are derived, explicitly incorporating atomic correlation and anharmonicity arising from nearest-neighbor interactions. Numerical results for Au reproduce the temperature- and wavenumber-dependent attenuation of the EXAFS amplitude and remain consistent with the reported experimental trends and uncertainties, particularly in the temperature region where the classical approximation is valid. The validity range of the classical treatment is quantified by the relative deviation between the quantum and classical mean-square relative (MSR) displacements, yielding a temperature threshold condition T >= 0.912 theta E, where theta E is the correlated Einstein temperature. A sensitivity analysis of the Morse potential parameters shows that the anharmonic force constants and EXAFS DW damping at high wavenumbers are especially sensitive to the potential-width parameter, whereas the overall temperature- and wavenumber-dependent behaviors remain robust. The analysis demonstrates that the present calculation model provides a physically transparent and computationally efficient framework for modeling temperature-dependent EXAFS DW factor in Au under thermal disorder. Because MSR displacement is obtained analytically from the AE potential and the statistical formalism, the present model can be incorporated into standard EXAFS fitting procedures as a physically constrained description of thermal damping in Au and related metallic systems.
Appropriate sample-to-flux ratios of fused borate glass bead specimens were investigated for igneous rock analyses. Severe interference of X-ray absorption and enhancement engenders erroneous findings from X-ray fluorescence spectrometric analyses, but light element dilution effects on glass bead specimens decrease this interference. The influences of several co-existing constituents were examined to compare 1:10 and 1:100 dilution ratios for igneous rock using synthetic glass bead specimens consisting of a sample, an additional co-existing element, and anhydrous lithium tetraborate. Effects of analytical lines on the X-ray fluorescence intensity of Mg, Ca, and Fe, which have markedly different concentrations in igneous rocks, were investigated using synthetic samples. For sodium, which has a low-energy (1.04 keV) analytical line, almost no effect occurred at a dilution ratio of 1:10 or 1:100. Because the energy of the analytical line (e.g., Al and Si) increases, the influence of co-existing elements was significant at 1:10 dilution. By dilution to 1:10, titanium and strontium were confirmed as showing XRF intensity attenuation of about 10%, strongly affecting quantitative values. Dilution to 1:100 led to negligible influence on the analysis by titanium (4.51 keV), a major component of igneous rock. However, because of the high dilution of analyte (1:100) and the large peak-to-background ratio, obtaining reliable XRF intensity from the minor strontium content was difficult.
X-ray fluorescence (XRF) logging technology serves as a critical analytical tool for deep mineral resource exploration and exploitation. However, the inherent geothermal gradient in deep borehole environments creates elevated ambient temperatures that adversely affect XRF measurement accuracy during logging operations. This study addresses the thermal regulation challenges in deep-borehole spectroscopic logging by proposing an innovative hybrid active-passive thermal regulation system for controlling probe temperature. Through comprehensive thermodynamic simulations using three-dimensional modeling software and experimental validation, it is demonstrated that the system can keep the performance of the detector under extreme thermal conditions. The results show that when exposed to temperatures up to 100 degrees C, the proposed system successfully maintains the probe temperature below 50 degrees C while ensuring stable detector operation for a minimum duration of 2 h.
A series of quantitative methods-the fundamental parameter (FP) and calibration curve methods-were evaluated for reliable routine analysis of archeological and geochemical silicic samples (e.g., pottery, clay, rock, and soil) using energy-dispersive X-ray fluorescence (EDXRF) spectrometry to determine their provenance. Calibration curves for 22 components (Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3, V, Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, and Pb) were constructed from 12 geochemical reference materials (RMs). A total of 15 of the 22 components exhibited poor linearity, with correlation coefficients of 0.774-0.987. The accuracy of the calibration curve, standardless FP, and FP methods calibrated with 12 RMs was evaluated by measuring six additional geochemical RMs. Comparison with the recommended values showed that the FP method calibrated with RMs was the most accurate, whereas the calibration curve and standardless FP methods showed comparable, but lower, accuracy. These results indicate that, for EDXRF analysis of archeological and geochemical silicic samples, the FP method calibrated with RMs is more appropriate and less time-consuming than constructing calibration curves. Furthermore, the number of RMs used to calibrate the FP method was reduced from 12 to 6, and the reliability was evaluated by measuring the same six additional geochemical RMs. The results showed that the FP method calibrated with 12 and 6 RMs achieved generally equivalent accuracy, indicating that the number of RMs can be reduced without compromising reliability, thereby lowering the calibration effort.
In this work, we investigate the feasibility of using Energy-Dispersive Inelastic X-ray Scattering (EDIXS) to extract structural information analogous to that obtained from Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. A set of four well-characterized vanadium reference samples (metallic V and the oxides V2O3, VO2, and V2O5) was selected to cover a wide range of oxidation states and local coordination environments. EDIXS spectra were smoothed using a high-frequency band-pass filter based on the instrumental response function, and the main emission line was fitted and subtracted to recover residual oscillations. These oscillations were treated as a surrogate chi(k) function and analyzed using Fast Fourier Transform (FFT) procedures identical to those applied in standard EXAFS analysis. The resulting FFT magnitudes from EDIXS were compared with those obtained from independently measured EXAFS spectra. In most cases, the apparent first-shell distance R 1 extracted from EDIXS agreed with the corresponding EXAFS value within statistical uncertainty, demonstrating that the EDIXS-derived residuals contain genuine structural information. A quantitative statistical comparison was performed using a normal-distribution z-test with alpha = 0.05, confirming equivalence in three out of four cases. These results show that, under appropriate filtering and analysis conditions, EDIXS spectroscopy can provide semi-quantitative structural information and may serve as a complementary technique to EXAFS, particularly in systems where conventional absorption measurements are difficult or impossible. The approach presented here opens new possibilities for exploiting inelastic scattering spectra in structural and chemical analysis.
Over the past 5 years, computer applications have become crucial to archeological research. Since the 1990s, the focus has transitioned from data management tools to the development of virtual models. Recently, digital documentation of cultural heritage has gained considerable focus, with 3D modeling of objects. The rendering and integration of images from micro-CT (Micro Computed Tomography) and XRF mapping techniques are essential for analyzing artworks and cultural heritage. Micro-CT provides detailed internal views of objects with high resolution, allowing examination without damage. Meanwhile, XRF mapping analyzes the surface composition of artworks, identifying materials and pigments. Combined, these methods deliver a thorough understanding of the structure and composition of cultural artifacts. However, these techniques are typically applied independently, and there is still a lack of integrated frameworks that enable the correlation of structural and compositional data within a unified 3D environment. This article investigates the fusion of 3D imaging techniques through an open-source software package to create a comprehensive multimodal visualization that integrates micro-CT and XRF mapping. The proposed methodology facilitates the automatic registration of surface scans and interactive visualization of aligned 3D images. The study integrates XRF mapping and micro-CT data to analyze cultural heritage artifacts, employing the Micro-XRF M4 Tornado (Bruker) and Crono (Bruker) for elemental mapping and micro-CT was conducted using the Phoenix VTomex system, and the data was reconstructed using the Datos Reconstruction software. Image rendering utilized a Blender plugin to integrate 3D imaging modalities, combining CT data with surface scan data. Beyond the individual capabilities of each technique, the integration of micro-CT and XRF plays a fundamental role in the analysis of wooden cultural artifacts. This combined approach enables the identification of pictorial materials and supports inferences regarding their provenance, while also contributing to the understanding of manufacturing processes, including carving techniques, preparation layers, and later interventions. The correlation between structural and compositional information enhances the interpretative potential in cultural archeology and provides more robust support for conservation and restoration strategies.
