ABSTRACT Spatial localization of various essential dietary elements present in a black wheat ( Triticum aestivum L .) grain has been investigated using synchrotron assisted micro X‐ray fluorescence measurements at BL‐16 beamline of Indus‐2 synchrotron facility. The results showed that most of the important dietary minerals like calcium (Ca), potassium (K), manganese (Mn) and iron (Fe) are present in the aleurone and scutellum regions of a grain and they exhibited positive co‐localization among themselves except Ca and Mn, which were localized in the outer part of bran layer region. However, in the case of crease tissue region of the wheat grain, relatively higher amount of zinc (Zn) exists which shows positive correlation with copper (Cu). These results are found to be in close agreement with the earlier investigations of other varieties of wheat grains. Our results show that using synchrotron assisted microprobe X‐ray fluorescence measurements at BL‐16 beamline of Indus‐2 synchrotron facility, it is possible to collect high quality X‐ray fluorescence images to determine elemental heterogeneity in a biological specimen especially those comprising of low Z (hydrogen, carbon, oxygen) matrix.

ABSTRACT The aim of this work was to evaluate cortical porosity through high‐resolution peripheral quantitative microtomography in a group of 46 patients, 23 controls, and 23 patients with Cushing's syndrome along the aging process, all women. All patients, in vivo, were submitted to the medical care protocol of the “Clementino Fraga” University Hospital, 020–213. Control patients are female in the age group from 37 to 82 years, who did not have fractures in lower and upper limbs, all of them showing good health. Patients with Cushing's syndrome were in the age group from 29 to 72 years. The results showed that the amount of pores in the cortical bone of patients with Cushing's syndrome increased with age, and there was also an increase in the diameter of these pores; however, a decrease in the border between cortical and trabecular bone was observed. Increase in cortical porosity with aging was also observed in the control group. The disease analyzed is not very common, making it difficult to analyze a larger group of individuals at this Hospital.

This special issue of X-Ray Spectrometry is dedicated to the works presented at the 17th Latin American Seminar on Analysis by X-Ray Techniques (SARX 2024). The event took place in Rio de Janeiro, Brazil, from November 4 to 6, 2024, and was organized by the Rio de Janeiro State University in collaboration with the Federal University of Rio de Janeiro, the Federal Institute of Rio de Janeiro, and the Santa Cruz State University. Financial support was provided by the National Council for Scientific and Technological Development (CNPq) and the Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro (FAPERJ). The SARX seminar is an international meeting that has been held biennially since 1990 across different Latin American countries. It brings together leading researchers worldwide to foster the exchange of knowledge and advances in X-ray-based analytical techniques. Over the years, SARX has become a recognized platform for presenting new developments in areas such as X-ray fluorescence (XRF), X-ray diffraction (XRD), X-ray imaging (XRI), X-ray absorption spectroscopy (XAS), and particle-induced X-ray emission (PIXE), with applications spanning materials science, chemistry, radiation physics, medicine, biology, environmental sciences, cultural heritage, technology, and industry. SARX 2024 welcomed 115 participants from 10 countries. The scientific program included 30 oral presentations, among them 14 invited lectures delivered by distinguished experts in X-Ray Spectrometry, and 44 poster presentations, providing a broad range of opportunities for participants to share and discuss their research. Beyond the formal sessions, the seminar also offered a valuable environment for networking and scientific exchange. The next SARX meeting will be hosted in Ilhéus, Brazil, under the coordination of Dany Sanchéz Dominguéz from the Santa Cruz State University. We wish them every success in continuing this important scientific tradition. We would also like to express our gratitude to all those who contributed to the success of SARX 2024. In particular, the support of young members of the local organizing committee was essential both in the preparation and throughout the event. The manuscripts gathered in this special issue of X-Ray Spectrometry were handled by the guest editors Prof. Davi Oliveira (COPPE/UFRJ), Roberta Leitão (COPPE/UFRJ), and Renato Freitas (IFRJ) and underwent the standard XRS peer-review process. We gratefully acknowledge the reviewers for their valuable contributions. We are confident that all the papers provide an accurate reflection of the scientific content presented during the conference. Thank you and look forward to meet you at SARX 2026. The authors declare no conflicts of interest. Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

ABSTRACT Unlike bulk analysis, thin film compositional analysis necessitates considering substrate effects, such as secondary fluorescence induced by x‐rays generated in the substrate and backscattered electrons. Several methods have been proposed to address these challenges. This study examines the influence of secondary fluorescence induced by characteristic x‐rays from the substrate on the film composition as determined by the method employed in JEOL's EPMA system. A CuAlO 2 film deposited on a Si substrate was selected as the representative specimen, given that the effect of secondary fluorescence induced by characteristic x‐rays of the Si substrate is substantial, due to the absorption edge energy of Al being slightly lower than that of the Si K α line. The findings reveal that the Si K α line generated from the Si substrate affected the generation of secondary Al K α fluorescence in the CuAlO 2 film when the film thickness was 200 nm or less. This interference can be mitigated through either depositing a 500 nm‐thick Au layer on the Si substrate or by depositing a CuAlO 2 film with a thickness exceeding 500 nm.

ABSTRACT The spatial distribution of trace elements (Mn, Sr, S, and P) in freshwater and seawater pearls was systematically investigated using micro‐X‐ray fluorescence (micro‐XRF) mapping combined with ultraviolet–visible–near infrared (UV–Vis–NIR) reflectance spectroscopy, Raman spectroscopy, and energy‐dispersive X‐ray fluorescence (EDXRF) spectroscopy. Results revealed distinct concentric Mn/Sr‐enriched spherical zones in the nacreous layer of freshwater pearls, with 3–4 zones in non‐nucleated pearls and 2–3 zones in nucleated ones. In contrast, seawater pearls exhibited uniform Sr‐ distribution without concentric enrichment patterns. Notably, Mn and Sr co‐enriched zones were consistently observed in all studied freshwater pearls, regardless of nucleation status. Furthermore, S and P exhibited homogeneous distributions in freshwater and seawater pearls. It is preliminarily considered that the concentric Mn/Sr‐ co‐enrichment patterns in freshwater pearls are attributed to environmental fluctuations, such as temperature variations and nutrient availability. The thickness of individual enriched zones and the spacing between adjacent zones may be a record of mineralization rates, indicating environmental changes during cultivation. In contrast, the stable marine environment of seawater pearls should result in uniform Sr distribution, with minimal Mn incorporation. These findings advance our knowledge of the biomineralization mechanisms of pearls and the gemological distinctions between freshwater and seawater pearls. More importantly, this work not only establishes diagnostic criteria for pearl origin identification, but also offers preliminary insights into the potential environmental implications of pearl cultivation, which may inspire further research into its role in water quality management and ecological restoration.

ABSTRACT The daguerreotype, introduced by Louis‐Jacques‐Mandé Daguerre in 1839, marked the beginning of photography. This early photographic process, based on halide‐sensitized silver‐coated copper plates developed with mercury vapor, produces highly reflective, image‐bearing surfaces that are both visually unique and chemically complex. As part of the interdisciplinary Heritage Science project PHELETYPIA, this study investigates the surface morphology and elemental composition of two historical daguerreotypes from the Varaždin City Museum (Croatia) using monochromatic micro‐x‐ray fluorescence (μXRF), scanning electron microscopy with energy‐dispersive x‐ray spectrometry (SEM/EDS), and optical microscopy. By comparing elemental distribution maps based on Hg‐L and Au‐L lines, we assess the relationship between image particle composition, visual contrast, and degradation patterns. Our results suggest that differences in image formation and preservation are linked to original manufacturing processes, including uneven thermal development and subsequent environmental exposure. High‐resolution elemental imaging reveals how visual information is distributed across tonal zones and how it may be affected by previous conservation interventions. These findings highlight the potential of non‐invasive analytical imaging to enhance our understanding of daguerreotype image structure, support condition assessment, and inform long‐term digital preservation strategies.

ABSTRACTThe Orgueil meteorite is of particular importance in the study of prebiotic chemistry and planetary formation processes. In this study, trace analysis and depth‐selective imaging of Orgueil meteorite fragments were performed using total reflection X‐ray fluorescence (TXRF) and confocal micro X‐ray fluorescence (CM‐XRF). Using TXRF for trace analysis, 12 elements were detected nondestructively. Notably, this method enabled simultaneous multielement analysis, which was more convenient than common destructive techniques, such as inductively coupled plasma–mass spectrometry (ICP‐MS). Furthermore, the presence of Hg was confirmed; given that Hg is expected to burn off during atmospheric entry, its detection is intriguing. In the CM‐XRF analysis, polycapillary lenses were placed in front of both the detector and the X‐ray tube to collect X‐ray fluorescence information in the region where the two X‐ray beams overlapped. Three‐dimensional elemental images were obtained by scanning the sample, wherein images of the Ca, Cr, and Fe components were acquired. Although the Fe and Cr images were comparable, a distinct elemental distribution was observed for Ca. Additionally, porous structures were observed in the elemental distribution images. These results suggest that the Orgueil meteorite exists as a porous material. The nondestructive application of TXRF and CM‐XRF techniques to valuable meteorite samples can provide useful information and should be performed prior to precision analysis such as ICP‐MS.

ABSTRACTThe development of high‐performance materials is critical for technology in every aspect of energy storage/converting devices. This study investigates the structural, electronic, and thermal properties of γ‐NaFeO2, a semiconductor, a promising cathode, and a thermoelectric material. This research aims to elucidate the mechanisms that enhance its performance, offering insights into its potential applications in next‐generation energy solutions. By analyzing its properties in detail, it is hoped to pave the way for the development of more efficient and sustainable energy storage and conversion technologies. By using Density Functional Theory (DFT) calculations and X‐ray Absorption Fine Structure (XAFS) spectroscopy, the material's electronic band structure, density of states (DOS), and how it behaves at different temperatures are explained. The results reveal strong Fe–O bonding and a stable crystal framework, with a direct bandgap of 0.701 eV. XAFS analysis confirms the robustness of the Fe coordination environment under elevated temperatures, while Fourier‐transform EXAFS (FT‐EXAFS) data provide insights into atomic distances and coordination numbers. The Debye‐Waller Factor (DWF) analysis highlights the material's thermal stability, with minimal structural degradation observed up to 100°C.

ABSTRACTThe measurement of the elemental composition of atmospheric Particulate Matter (PM) is of paramount importance in air pollution studies, providing fundamental information for identifying aerosol sources and understanding their contributions. In this context, online instruments integrating an energy‐dispersive X‐ray fluorescence (ED‐XRF) spectrometer into an aerosol sampler offer the capability to both collect PM and perform near‐real‐time elemental analysis. However, these instruments face limitations, particularly in detecting low‐Z elements such as Na, Mg, and Al, which are critical tracers for natural PM sources. In order to investigate potential solutions to this limitation, different technical solutions were implemented on a compact ED‐XRF spectrometer that was developed for this specific purpose. The spectrometer's performance was evaluated through comparative analyses with a commercially available online metals analyzer for PM (Xact 625i) and particle induced X‐ray emission (PIXE) technique. Results demonstrated greater sensitivities and lower MDLs for low‐Z elements compared to a commercial online spectrometer for PM (Xact 625i) while scatterplots of measured elemental concentrations showed good correlation with both Xact 625i and PIXE. Moreover, fairly good MDLs, even if higher than those of Xact 625i, were achieved also for mid‐high‐Z elements. Finally, the spectrometer also demonstrated its capability to analyze PM samples collected on filters of various sizes, beyond the commonly used 47 mm diameter ones, overcoming the typical limitations of standard ED‐XRF benchtop instruments.