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Funding Information: This work was partially supported by the research centre grant UID/FIS/04559/2021 to LIBPhys-UNL from the FCT/MCTES/PIDDAC , Portugal. Publisher Copyright: © 2023 The Authors One of the most widely used methods for tissue preservation and fixative during transportation is the conservation in formalin during variable amounts of time. In this study, we have evaluated the influence of formalin fixation time in the elemental composition of human tissue samples using Energy Dispersive X-Ray Fluorescence (EDXRF). Ten sets of human tissue samples (from colon, ileum, stomach, and spleen) were exposed to different formalin fixation times, between 2 and 24 days, and for each tissue, the elemental content throughout time was compared to the elemental content of the snap-frozen sample of the same tissue that was not exposed to formalin. Additionally, in order to further evaluate the transference of elements, the formalin solution was also analysed using EDXRF. Our results showed a clear decrease of Cl and K in the tissues, transferred to the formalin solution. Conversely, there is an uptake of P in the tissue, likely due to the buffered formalin solution. The consistent alterations seen in the studied elements across all the ten different tissues allow us to hypothesize that in the future, there will be different thresholds for their use as diagnostic tools in unfixed (intraoperative exams) as well as formalin fixed paraffin embedded tissues. publishersversion published

Authors acknowledge Centro Hospitalar Barreiro-Montijo for allowing the current investigation and providing the samples. Publisher Copyright: © 2023 The Authors In this work we present a methodology for the non-destructive elemental determination of formalin-fixed paraffin-embedded (FFPE) human tissue samples based on the Fundamental Parameters method for the quantification of micro Energy Dispersive X Ray Fluorescence (micro-EDXRF) area scans. This methodology intended to overcome two major constraints in the analysis of paraffin embedded tissue samples – retrieval of optimal region of analysis of the tissue within the paraffin block and the determination of the dark matrix composition of the biopsied sample. This way, an image treatment algorithm, based on R® tool to select the regions of the micro-EDXRF area scans was developed. Also, different dark matrix compositions were evaluated using varying combinations of H, C, N and O until the most accurate matrix was found: 8% H, 15% C, 1% N and 60% O for breast FFPE samples and 8% H, 23% C, 2% N and 55% O for colon. The developed methodology was applied to paired normal-tumour samples of breast and colon biopsied tissues in order to gauge potential elemental biomarkers for carcinogenesis in these tissues. The obtained results showed distinctive biomarkers for breast and for colon: there was a significant increase of P, S, K and Fe in both tissues, while a significant increase of Ca an Zn concentrations was also determined for breast tumour samples. publishersversion published

Micrometric 2D mapping of distinct elements was performed in distinct soil grain-size fractions of a sample using the micro-X-ray Fluorescence (µ-XRF) technique. The sample was collected in the vicinity of São Domingos, an old mine of massive sulphide minerals located in the Portuguese Iberian Pyrite Belt. As expected, elemental high-grade concentrations of distinct metals and metalloids in the dependence of the existent natural geochemical anomaly were detected. Clustering and k-means statistical analysis were developed considering Red–Green–Blue (RGB) pixel proportions in the produced 2D micrometric image maps, allowing for the identification of elemental spatial distributions at 2D. The results evidence how elemental composition varies significantly at the micrometric scale per grain-size class, and how chemical elements present irregular spatial distributions in the direct dependence of distinct mineral spatial distributions. Due to this fact, elemental composition is more differentiated in coarser grain-size classes, whereas griding-milled fraction does not always represent the average of all partial grain-size fractions. Despite the complexity of the performed analysis, the achieved results evidence the suitability of µ-XRF to characterize natural, heterogeneous, granular soils samples at the micrometric scale, being a very promising investigation technique of high resolution.

International audience; The EU Renewable Energy Directive with climate and energy goalsdoes not leave room for coal-burning power plants that currentlycontribute approximately 17 million t of flue gas desulfurization (FGD)gypsum to EU manufacturers that require a total of 57 million t ofgypsum per year (EU, 2020). It is also unlikely that natural gypsumproduction in the EU can be significantly increased in the near-term.Unlike other critical raw materials (CRMs) such as rare earth elements(REEs) that constitute a relatively small volume and can be importedover long-distances, such practice is not economically feasible for thisrelatively inexpensive (per weight) bulk-commodity used in largequantities. Transport costs for natural gypsum easily surpass the productvalue, so that imports would measurably increase prices for constructionin the EU and affect millions.

The C2TN XMS-PIXE system based on a first generation X-ray Microcalorimeter Spectrometer (XMS) having 1.5% relative energy resolution at Si K α 1.739 keV and 0.5% relative energy resolution at Fe K α 6.403 keV, became operational in 2008, presaging various developments to emerge from its use and from connected or related but independent advancements by other laboratories. More than ten years having passed since the C2TN XMS-PIXE system first results, knowledge about XMSs use for PIXE has grown meaningfully and new applications are now envisaged and in progress. In the present work, results on the analysis of different copper compounds are presented, and used as an assessment of the capacity of High Resolution Energy Dispersive PIXE (HiRED-PIXE) to provide answers to the problem of copper pigments speciation in Cultural Heritage studies. Related issues of XMS spectra generation and calibration are discussed, as well as first generation systems limitations and its overcome by the use of second and third generation systems.

This contribution describes the study conducted on two painted wooden reliefs created in the early 1970s by Vasko Lipovac, a prominent Croatian contemporary artist. Due to the poor condition in which the artworks were found, it was important to establish a strategy for conservation and long-term preservation. Accordingly, preliminary knowledge about chemical composition of the paint pigments and binders was pointed out as significant information addressed in this study. Since the chemical composition of the paint determines the conservation methodology and materials, the proper treatment ensures stability of the original materials, and accordingly, long term preservation of an artwork. An integrated analytical approach involving different instrumental analytical techniques was applied to each of the microsamples collected in the paintings. For the elemental characterization of the pigments, total reflection X-ray fluorescence spectroscopy (TXRF) was used, and the obtained results were complemented with the information about mineral phases present in the pigments by X-ray diffraction (XRD) analysis. The TXRF results demonstrated that most of the pigments related with the named “skin tone” contain appreciable amounts of Cd (1.8–9%) with constant presence but variable amounts of Se (0.24–1.1%), reinforcing the interpretation that the pigment originally used is cadmium sulfoselenide (the so-called “cadmium red”), although by XRD we only observed the presence of its alteration to cadmium sulfate. The XRD results revealed a complex mixture of different inorganic compounds present in the painted wooden reliefs (i.e., barite, rutile, quartz, calcite, chlorite, etc). The presence of zinc white with wurtzite structure in almost all the samples can be considered as the main constituent of the coloring painting layer. Raman spectroscopy contributed to a more accurate characterization of the analysed paint samples, since the vibrational spectra as a result of Raman scattering proved very useful to obtain information on the presence and type of the synthetic pigments. Fourier transform infrared spectroscopy (FTIR) and pyrolytic gas chromatography coupled with mass spectrometry (Py-GC/MS) were used to determine the chemical composition of the paint samples binders. Py-GC/MS clarified the doubts about acrylic and alkyd components in paints where polyvinyl acetate (PVAc) is predominant by detecting acrylate monomers and phthalic anhydrides and provided information about their relative presence in the samples. On the other hand, FTIR spectroscopy was a necessary tool for unambiguous identification of nitrocellulose in the white and black samples from one of the paintings, as well as for the firm assumption of its presence in most of the other samples since Py-GC/MS is not suitable for its detection., Authors want to acknowledge Dimitra Papadopoulou (Aristotle University of Thessaloniki, Greece) for her support in the laboratory work. IDAEA-CSIC is a Centre of Excellence Severo Ochoa (Spanish Ministry of Science and Innovation, Project CEX2018-000794-S). “This article/publication is based upon work from COST Action CA18130 ENFORCE TXRF, supported by COST (European Cooperation in Science and Technology).” COST (European Cooperation in Science and Technology) is a funding agency for research and innovation networks. Our Actions help connect research initiatives across Europe and enable scientists to grow their ideas by sharing them with their peers. This boosts their research, career and innovation.

The main goal of this study was to identify potential chemical elements present in three types of polymetallic mine waste, stored in the old mine site of Sao Domingos, located in the Iberian Pyrite Belt, Alentejo, Southern Region of Portugal. This study involves the characterization of potential resources in those mine residues, bearing in mind that its reprocessing can facilitate the environmental remediation and rehabilitation activities which are underway at the site. X-ray Fluorescence (XRF) and micro (μ)-XRF 2D mapping surveys were performed. Univariate and multivariate data analysis reveal that differences in compositions are mainly related with element concentration per type of waste. Image processing and clustering analysis allowed the recognition of distinct elemental spatial distribution patterns. Some of these residues, although classified as archeological-industrial heritage materials may present toxicity to the ecological environment and to human health. This fact enhances, therefore, geoethical doubts regarding its remining and exploitability. In this context, a multi-criteria decision analysis considering two geoethical alternatives was performed.

The importance of fluoride (F) for oral health is well established in the literature. However, evidence suggests that excessive exposure to this mineral is associated with adverse effects at different life stages and may affect many biological systems, especially mineralized tissues. The purpose of this study was to investigate the effects of F exposure during pregnancy and breastfeeding on the alveolar bone of the offspring since the alveolar bone is one of the supporting components of the dental elements. For this, the progeny rats were divided into three groups: control, 10 mg F/L, and 50 mg F/L for 42 (gestational and lactation periods). Analysis of the quantification of F levels in the alveolar bone by particle-induced gamma emission; Raman spectroscopy to investigate the physicochemical aspects and mineral components; computed microtomography to evaluate the alveolar bone microstructure and analyses were performed to evaluate osteocyte density and collagen quantification using polarized light microscopy. The results showed an increase in F levels in the alveolar bone, promoted changes in the chemical components in the bone of the 50 mg F/L animals (p < 0.001), and had repercussions on the microstructure of the alveolar bone, evidenced in the 10 mg F/L and 50 mg F/L groups (p < 0.001). Furthermore, F was able to modulate the content of organic bone matrix, mainly collagen; thus, this damage possibly reduced the amount of bone tissue and consequently increased the root exposure area of the exposed groups in comparison to a control group (p < 0.001). Our findings reveal that Fcan modulate the physicochemical and microstructural dimensions and reduction of alveolar bone height, increasing the exposed root region of the offspring during the prenatal and postnatal period. These findings suggest that F can modulate alveolar bone mechanical strength and force dissipation functionality., This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. R.R.L is a researcher from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and received grant under number 312275/2021-8. Also this research was funded by PROCAD Amazônia – CAPES (23038.005350/2018–78).

Acoes Integradas Luso-Francesas, Acao Ref. TC08-17; Programa Pessoa 2017-2018; EMPIR, Grant/Award Number: 17FUN02 MetroMMC; FCT (Portugal), Grant/Award: SFRH/BPD/94234/2013; FCT, Grant/Award Number: PTDC/FIS-AQM/31969/2017. Zinc K-shell radiative and radiationless transition rates are calculated using the multiconfiguration Dirac–Fock method. Correlation up to the 4p orbital is included in almost all transition rate calculations. Calculated radiative transition rates and transition probabilities are compared with Scofield's Dirac–Hartree–Slater and Dirac–Hartree–Fock calculations, presenting good agreement with the later. Radiative transition intensity ratios involving the strongest lines are compared with theoretical, experimental, and empirical-fit values. Most ratios are in close agreement with the empirical-fit values from NIST's Fundamental Parameters database. Calculated radiationless transition rates and ratios are compared with Chen et al.'s Dirac–Fock values and Safronova et al.'s Dirac–Fock values. The K-LL transition rates are overall lower than Chen et al.'s values, whereas the K-LX and K-XY transition rates are overall higher. Calculated K-LX/K-LL and K-XY/K-LL ratios are relatively close to the experimental values compared. Some calculated intensities relative to K-L2(1D2) are in good agreement with the experimental values, whereas others present worse agreement. The calculated fluorescence yield is higher than all theoretical, experimental, and empirical-fitted values compared, probably because the total radiationless transition rate value calculated in the present work is relatively low. publishersversion published

Fundacao para a Ciencia e Tecnologia for financial support (Post-doc grant SFRH/BPD/103315/2014) through program QREN-POPH-typology 4.1., co-participated by the Social European Fund (FSE) and MCTES National Fund. Also acknowledge Joaquim Rodrigues dos Santos, Doris Santos, Arterestauro, Lda. and Claudia Bento at BC-DGPC and LJF-DGPC. In this work we address the study of three groups painted by Josefa d' Óbidos (1630–1684) and by her father Baltazar Gomes Figueira (1604–1674). These painters were the most important pair working in the 17 th century in Portugal with a Proto-Baroque style and the materials and techniques used by their workshop are almost unknown. Analytical procedures employed to characterize the materials and painting techniques involve molecular spectroscopy with μ-Confocal Raman (μ-Raman) and Fourier Transform Infrared Spectroscopy (μ-FTIR) in combination with other complementary methods such as X-ray Fluorescence Spectroscopy (XRF), μ-X-ray diffraction (μ-XRD) and Scanning Electron Microscopy with Energy Dispersive spectroscopy (SEM-EDS). Results are compared with the instructions of the most significant coeval Iberian painting treatises, with influence on Óbidos workshop. Conclusions of this study bring the first insight on the materials used, technical procedures and evolution from panel to canvas of Óbidos painting workshop, particularly highlighting the work of Josefa d' Óbidos, the greatest female Portuguese painter of all times. authorsversion published

In this work, we present the combined use of in situ X ray Fluorescence spectroscopy and Monte Carlo simulation using PENELOPE code for the completely non-invasive determination of gold leaf thickness in artworks using lead white as mordant. The methodology used is based on the detection of different characteristic lines of Pb in the X ray fluorescence spectra, attenuated trough the gold leaves, and determining the thickness of gilding by comparing their attenuation. Firstly, this methodology was calibrated using model samples of simple stratigraphy, namely pure Au leafs of 1, 2 and 2.5 μm thickness covering a Pb infinitely thick sheet. The modelled X ray setup was then used to study the gilding thickness of three panel paintings belonging to the Museum of Christian Art in Old Goa (India): two paintings, from the 18th century, concerning to the same series but different themes: Our Lady of Sorrows (MoCA1) and Our Lady of Seven Sorrows (MoCA2), and a third painting entitled Monstrance (MoCA3), from the 17th century. These panel paintings were analyzed to understand the differences and similarities between techniques, according to the time/epoch and technique of its manufacture. The obtained values for MoCA2 tend to be slightly lower than for MoCA1, however, the t student test revealed that the differences were not statistically different (p = .37). Regarding the MoCA3 painting, the average thickness was determined to be statistically different (p

In this work, we established a methodology for the analysis and characterization of hydroxyapatite-based materials using X-ray fluorescence. There are several animal hard tissues that can be recognized due to the relative amounts of hydroxyapatite (HAp) and collagen, using vibrational spectroscopy. The same principle can be applied to dental tissues to distinguish between enamel, dentine and root. Using X-ray fluorescence spectra, only the inorganic part can be identified and, sometimes, due to elevated P detection limits, mainly Ca can be detected. Therefore, we have established a methodology for hydroxyapatite recognition using reference samples, in order to obtain a calibration curve of the ratio of the Compton to Rayleigh scattering of the characteristic Kα line of the anode material as a function of the average atomic number of the sample. The reference samples consisted of different proportions of HAp [Ca10(PO4)6(OH)2] and boric acid [H3BO3] reference materials in order to obtain an average Z range of 7 to 14. This calibration curve was developed for a portable X-ray fluorescence setup with triaxial geometry and applied to: ivory jewelry and decorative objects from different origins, with the purpose of establishing differentiation markers, and human teeth before and after erosion processes for demineralization assessment.

The purpose of this work was to study the adhesive interface created, with an universal adhesive system (Futurabond M+), between two types of dentin substrates and a restorative material. To fulfill this purpose, we evaluated both the degree of conversion (DC) of the adhesive system and the degree of demineralization (DD) of the dentin, using μ-Raman Spectroscopy, and the morphology of the adhesive interface under Scanning Electron Microscopy (SEM). Two types of dentin were used – sound, from a healthy tooth, and affected, collected from the deepest layer of a carious lesion, without bacteria, partially demineralized however physiologically remineralizable. The universal adhesive system was applied using two available modes - etch-and-rinse (ER) and self-etch (SE). Analyses were performed after 24 h and 6 months of the restorative procedure. Significant differences were found between adhesive modes in the DD of sound substrate specimens after 6 months aging and in the DD of affected substrate specimens, after 24 h and 6 months aging. Average DD values were, overall, higher with the ER mode. Average DC values ​were substantially high (DC ≥ 78%) overall, independently of the experimental group analised. DC values were on average lower ​​closer to the dentin substrate and higher closer to the adhesive layer. The morphology of the interface was consistent with the results obtained by the μ-Raman Spectroscopy technique.

In this work, we present a novel application of the full-field energy-dispersive X-ray fluorescence (EDXRF) imaging system based on a MicroPattern Gaseous Detector (2D-THCOBRA) in the cultural heritage field. The detector has an intrinsic imaging capability with spatial resolution of $$400\,{\upmu }\mathrm { m}\ \mathrm {FWHM}$$ , and is energy sensitive, presenting an energy resolution of approximately $$1\ \mathrm {keV\ FWHM}$$ at $$5.9\ \mathrm {keV}$$ . The full-field XRF scanner based on the 2D-THCOBRA detector allows mapping the distribution of elements in large area samples with high detection efficiency ( $$75\%$$ at $$5.9\ \mathrm {keV}$$ ), being a very promising choice for elemental mapping analysis of large area cultural heritage samples. In this work, we have demonstrated the imaging capabilities of the full-field XRF scanner and used it to assess the restoration of a Portuguese faience piece.

Raman spectroscopy is nowadays regarded as a practical optical method and non-destructive photonic tool, which can be applied in several biomedical fields for analyzing the molecular composition. This technique is considered appropriate for human dental tissues characterization, from caries detection to evaluation of demineralization caused by acidic external agents. Discrimination techniques (linear regression), and classification techniques (neural networks) are often used for spectroscopic data analysis in disease detection and identification. Usually, Raman raw spectra obtained from teeth are processed using baseline correction, smoothing, normalized for noise, fluorescence, shot noise removal, and subsequently analysed using principal component analysis, to reduce the variable dimensionality. Raman chemical images can be constructed with another simple and uncomplicated unsupervised machine learning method – represented by k-means clustering, enabling the identification of similar areas/features, for classifying different acquired spectral data. The Machine Learning methods choice depends always on type and amount of information provided by Raman spectra. In this paper, was applied Principal Component Analysis methods to the analysis and interpretation of several parameters extracted from Raman spectra acquired before and after a simulated acid challenge of human enamel. These parameters and their correlation allow to assess the protective effect of a fluoride-based dental varnish.

Aluminum (Al) is one of the most found elements in nature in many forms, and human exposure can be quite common. Therefore, it is important to investigate the effects of exposure to Al mainly at low doses and for a prolonged period, in order to simulate human exposure in the periodontium, an important structure for support and protection of the teeth. This investigation aimed to study the aluminum chloride (AlCl3) toxicological effects in the mineral composition and micromorphology of the alveolar bone of rats. Two groups of eight male Wistar rats were used for the experiment. AlCl3 group was exposed to AlCl3 orally at a dose of 8.3 mg/kg/day for 60 days, while the control group received only distilled water. After that, the mandibles were collected and submitted to the following analyses: Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray microtomography analysis; blood was also collected for determination of Al circulating levels. Our data showed that AlCl3 was capable of increasing Al circulating levels in blood. It was able to promote changes in the mineral content and triggers significant changes in the mineralized bone microstructure, such as number and thickness of trabeculae, being associated with alveolar bone-loss.

UID/FIS/04559/2019 to LIBPhys-UNL from the FCT/MCTES/PIDDAC, Portugal. FCT contract No. PD/BD/128324/2017. In this work, we aim at achieving the most accurate quantitative determination of elements in human tissues by means of X-ray Fluorescence spectrometry using the external calibration approach. A calibration curve built using a set of certified reference materials (CRM) of animal tissue was compared with the one obtained with a set of CRMs of plants and leaves with lower atomic number Z but with correction of the matrix using the scattering peaks of the X-ray tube anode. Finally, a calibration curve combining the two sets of CRMs was built and the accuracy of the quantification using the three methods was compared and a more precise method of quantification was obtained. This improved approach was tested on five paired samples of normal and tumour human tissue. Despite the high heterogeneity of the samples, and given the improvement in accuracy of the measurements, significant differences were found in the elemental concentration of low-Z elements. This journal is authorsversion published

PTDC/FIS-AQM/31969/2017 Programa Pessoa 2017-2018, Proc. N 441.00 France SFRH/BPD/94234/2013 Grant/Award Number: 17FUN02 MetroMMC The simulation of atomic relaxation relies on data libraries with tabulated partial fluorescence yield values of radiative transitions, commonly derived from the Evaluated Atomic Data Library (EADL). However, recent studies support that the data library EADL could be improved by adopting Scofield's Hartree-Fock calculations instead of current Scofield's Hartree-Slater calculations. This work presents a bibliography overview of relevant atomic parameter values in order to verify the partial fluorescence yields presented in EADL. The references include libraries and articles, in which the atomic parameter values were theoretically calculated, experimentally measured, or obtained with semi-empirical and empirical fitting formulas. We present a comparison of total K-shell fluorescence yields and partial K-L2, K-L3, K-M2, K-M3 fluorescence yields that are either obtained directly from its references, or are derived from atomic parameters presented in these references. Additionally, we obtain comprehensive partial fluorescence yield values from the combination of semi-empirical and empirical fitting functions from different references. The comparisons performed in this work confirm that total K-shell, partial K-L2, and partial K-L3 fluorescence yield values, obtained from Scofield's Dirac-Slater calculations have better agreement with the most recent empirical values. Partial K-M2, and partial K-M3 fluorescence yield values obtained from Scofield's Dirac-Fock calculation have better agreement with the most recent empirical values. Therefore, further studies should be performed before changing the EADL data library. publishersversion published

In-situ monitoring of potentially toxic elements in mining water samples is of special relevance in order to evaluate the environmental impact of abandoned mining activities. However, it is difficult to develop suitable analytical methods for this purpose considering the complexity of mining water samples matrix as well as the limited sensibility of conventional filed portable X-ray fluorescence spectrometry systems (pXRF). In the present contribution, a simple, sustainable and reliable triaxial pXRF method (3pXRF) is proposed for multielemental analysis of mining water samples. In this method, several microliters of sample are deposited onto a commercial filter paper retainer and after drying, the loaded filter is directly analyzed in the field using a laboratory pXRF with orthogonal triaxial geometry (p3XRF). This geometry reduces the background of the measured spectra improving peak-background ratios in comparison with conventional pXRF systems. Using the best analytical conditions (sample deposition volume of 200 μL and 600 s as measurement time), limits of detections were in the low mg∙L range and therefore suitable considering the expected high metal concentration in mining water samples. Acceptable accuracy and precision of the results was obtained in comparison with laboratory techniques such as inductively coupled plasma optical emission spectrometry and total reflection X-ray fluorescence spectrometry but with the possibility of in-situ measurements in the field. The developed method was applied to the analysis of different types of mine water samples (stream waters, drainage water tanks and mining lake waters) collected in the mining districts of Tinoca (Portugal) and Cartagena-La Unión (Spain)., S. Pessanha and M. L. Carvalho would like to acknowledge the financial support of Portuguese Foundation for Science and Technology in the funding of LIBPhys (project — UID/FIS/04559/2013). This work was also carried out in the framework of the project CGL2016-78783-C2-2-R funded by the Spanish R + D national Programme. I. Queralt also acknowledges a grant for a Sabbatical stay at Universidade Nova de Lisboa (ref. PRX16-00159) from the Spanish Ministry of Education. The authors thank M. Cabañas and R. Bartrolí (IDAEA-CSIC, ICP laboratories) for their analytical assistance.

In this in vitro study, the effect of the application of tooth bleaching products in human enamel was evaluated using polarized Raman microscopy, particle induced gamma-ray emission (PIGE) and Vickers Hardness test. Due to their acidic nature, teeth whitening products are associated with changes in enamel mineralization. Consequently, products have appeared in the market that promote the incorporation of fluorine in order to decrease the solubility of the hydroxyapatite in enamel and prevent demineralization. This way, four commercial products with different active principle concentrations: 16% carbamide peroxide (Opalescence PF® and VivaStyle®) or 6% hydrogen peroxide (Opalescence Go PF® and VivaStyle Paint On®) and presence or not of fluorine were compared. The information on the crystalline state of the enamel was provided by the determination of the depolarization ratio of the symmetric stretching band of phosphate (at 959 cm−1). Furthermore, the content and uptake of F was evaluated using PIGE in the two fluorinated products as well as in one negative control group. In order to evaluate the microhardness of enamel by means of Vickers test, another group of polished samples was prepared (using Opalescence PF®) and evaluated. Conversely to what could be expected, the obtained results determined a statistically significant decrease of depolarization ratio, leading to an increase of mineralization after the application of the bleaching products, except for VivaStyle®. For this group, no significant variation was obtained before-after treatment, most likely due to the acidity of the product (pH = 5.8). Additionally, an increase of concentration of F in the dental tissues was determined for the fluorinated products. On the other hand, enamel polishing, required for the application of the Vickers test, led to increased susceptibility to erosion, resulting in decreased hardness and an increased enamel depolarization ratio.

In this work the elemental composition of paper and ink belonging to two paper handwritten documents is compared using non-destructive Energy Dispersive X Ray Fluorescence. The two documents correspond to a real estate sales manuscript dating from 1555 and a more recent copy of the same transaction, of unknown origin. The findings obtained using this spectroscopic technique were confronted with the analysis of two paper samples using Scanning Electron Microscopy coupled to Energy Dispersive system, in order to further evaluate the presence of inclusions. Moreover, fiber identification was also pursued. The raw materials employed presented very similar between documents, however, elemental analysis of paper and ink have proven efficient in distinguishing both paper documents and both inks. The obtained results on the characterization of the materials are consistent with the paleographic analysis and watermark identification previously attempted that dated the copy document from the first half of the 18th century.

This work has been financially supported by Fundação para a Ciência e a Tecnolo-gia through the LIBPhys funding UID/FIS/ 04559/2021 Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This work explores the suitability of data treatment methodologies for Raman spectra of teeth using multivariate analysis methods. Raman spectra were measured in our laboratory and obtained from control enamel samples and samples with a protective treatment before and after an erosive attack. Three different approaches for data treatment were undertaken in order to evaluate the aptitude of distinguishing between groups: A—Principal Component Analysis of the numerical parameters derived from deconvoluted spectra; B—PCA of average Raman spectra after baseline correction; and C—PCA of average raw Raman spectra. Additionally, Hierarchical Cluster Analysis were applied to Raman spectra of enamel measured with different laser wavelengths (638 nm or 785 nm) to evaluate the most suitable choice of illumination. According to the different approaches, PC1 scores obtained between control and treatment group were A—50.5%, B—97.1% and C—83.0% before the erosive attack and A—55.2%, B—93.2% and C—87.8% after an erosive attack. The obtained results showed that performing PCA analysis of raw or baseline corrected Raman spectra of enamel was not as efficient in the evaluation of samples with different treatments. Moreover, acquiring Raman spectra with a 785 nm laser increases precision in the data treatment methodologies. publishersversion published

Background X ray Fluorescence has been essayed as a suitable technique for the elemental quantification of trace element in human tissues, namely comparison of normal and cancerous tissue. However, accurate results depend on a robust quantification approach, namely correct evaluation of the samples’ dark matrix. Methods In order to determine the most suitable dark matrix composition for the quantification of such samples using the Fundamental Parameter approach, we have measured several Certified Reference Materials and essayed different dark matrix compositions to achieve the most accurate results. The resulting dark matrix was then applied to normal and tumor ovarian and prostate tissue samples, and the obtained results were compared with the ones obtained with a comparative method using external standard calibration curves. Results Using a dark matrix composed of 10 % - H, 22 % - C, 3 % - N and 60 % - O yielded the best compromise in accuracy for the light and heavy elements. For the reduced sample size and conditions of this study, for both organs, the concentrations of transition metals decrease in tumor tissues, while the concentration of lighter elements, P and Cl, increases. On the other hand, there are elements that showed different behavior between the two types of tissue, namely Zn and S, that increase in prostate tumor tissue and decrease in ovarian tissue. Conclusion An increase in precision was one of the improvements found with the newly developed method, as the FP-approach contemplates matrix effects and the influence of other elements in the analytes’ quantification. Additionally, the determined dark matrix can be employed in any tissue analysis application by means of EDXRF.

In this work, we present a methodology for the determination of the depth of demineralization in dental enamel caused by extended use of an Over-The-Counter (OTC) whitening product. Teeth whitening is a very common practice in Dentistry, but concerns have been raised regarding the invasiveness of the treatment, especially regarding OTC products, that can be used without medical supervision and sometimes with concentrations of active agent that exceed the allowed regulations. In this work, we studied tooth enamel samples, treated with a whitening product during an extended period of time, both directly on the enamel surface and in the cross-section. Specimens were analyzed using microbeam X-Ray Fluorescence (micro-XRF) using polycapillary optics to obtain a spot down to 25 μm. Due to the relatively large spot size of our setup point analysis of the cross-sections would be inadequate. This way, line scans were performed instead, before and after whitening, and using appropriate data treatment the depth of demineralization was inferred. The used methodology indicated an average demineralization depth of 25 μm, the same order of magnitude as the aprismatic enamel layer.

In this work, we aim at achieving the most accurate quantitative determination of the composition of exoskeletons of bivalves from Tagus estuary with Energy Dispersive X-ray Fluorescence. Samples from the shells of clams ranging from the Bronze Ages to the 16th century A.D. belonging to the Museu Arqueologico de Almada, and also from the shells of clams collected recently in the same region, were analyzed for comparison of the trace element composition and detection of heavy metals. The analysis was performed with 2 Energy Dispersive X-ray Fluorescence setups, one with triaxial geometry and another with a conventional geometry and vacuum capabilities. Samples were pressed as pellets, and the spectra collected with both setups were evaluated using standardless fundamental parameter based software's implemented in each setup, and by comparing with standard reference materials of similar matrix. The comparison of the results obtained with different methods lead to the conclusion that the most realistic results were obtained with calibration curves obtained with external standards and correction the fluorescent intensities with the Compton scattering peak. When comparing the obtained concentrations for all the analyzed periods, results showed a decrease of Fe in the 12th Century. Regarding the environmental current state of the Tagus estuary, there were no heavy metals detected above the safety regulations.

A set of five manuscripts written by Sister Lucia between 1941 and 1944 were under study. Among them is the one that contains the description of the third part of the Secret of Fatima also known as the Third Secret of Fatima. In this work, a characterization of the paper and the ink used in these documents was achieved using micro-X-ray fluorescence spectrometry. Quantitative results were obtained for P, K, Ca, Fe, Cu and Zn, revealing different paper composition and Zn in the inks. 2D elemental maps confirmed that Zn was present in the five documents ink and that the manuscript revealing the Third Secret of Fatima contained no erasures or alteration attempts to the original manuscript.

Energy dispersive X-ray imaging can be used in several research fields and industrial applications. Elemental mapping through energy dispersive X-ray imaging technique has become a promising method to obtain positional distribution of specific elements in a non-destructive way. To obtain the elemental distribution of a sample it is necessary to use instruments capable of providing a precise positioning together with a good energy resolution. Polycapillary beams together with silicon drift chamber detectors are used in several commercial systems and are considered state-of-the-art spectrometers, however they are usually very costly. A new concept of large energy dispersive X-ray imaging systems based on gaseous radiation detectors emerged in the last years enabling a promising 2D elemental detection at a very reduced price. The main goal of this work is to analyze a contemporary Indian miniature with both X-ray fluorescence imaging systems, the one based on a gaseous detector 2D-THCOBRA and the state-of-the-art spectrometer M4 Tornado, from Bruker. The performance of both systems is compared and evaluated in the context of the sample's analysis.

In this paper, we study the performance of a portable energy dispersive X-ray fluorescence spectrometer by making use of different filter configurations at the X-ray tube output. To fulfill this purpose, we systematically investigated how the detection limits (DL) can be improved by applying three different combinations of filters (Al, Cu and Al + Cu) between the X-ray tube and standard reference materials of different average-Z matrices. The obtained results were compared with the DL obtained with a benchtop system with triaxial geometry, considered the benchmark in detection of trace elements in a variety of sample matrices. The major differences occurred for the low-Z matrices, reflecting the increase of DL for elements with emission energies between 5 and 15 keV using filters. Regarding the high-Z matrices, the use of filters did not render an effective improvement in the DL but had a positive effect in diminishing sum peaks that could hinder the evaluation of some elements. Copyright © 2016 John Wiley & Sons, Ltd.

Moroccan manuscripts heritage preserves valuable information regarding different fields of Arabian history and culture. Despite this fact, analytical studies carried out in Moroccan manuscripts are scarce. In this work, we made use of a multi-analytical methodology to study, for the first time, four illuminated manuscripts from the Royal library of Rabat covering the span 14th to 19th centuries. The chemical structure of inks and paper support was identified. Elemental distribution obtained by micro-energy dispersive X-ray fluorescence (μ-EDXRF) showed the use of iron, copper and vermillion in black, blue and red inks, respectively. Arsenic and lead were identified as orange inks in the 17th and 19th century manuscripts, respectively. Quantitative characterization of the paper supports obtained by triaxial geometry EDXRF spectrometry showed high levels of sulphur, chlorine and potassium. Regarding the study of the manuscripts support, cellulose $I_{\beta}$ was determined by X-ray diffraction (XRD) in all the analyzed samples. Cellulose fibers observations by scanning electron microscopy showed that the manuscripts are in general, in a good condition. Calcite is the main filler determined by XRD.

In this work, we compared the accuracy of gold leaves thickness determination using X-ray Fluorescence (XRF) setups for different X-ray excitation sources. The sources used consisted on: a) direct Bremsstrahlung from an Amptek Mini-X X-ray tube with Rh target, b) partially monochromatized radiation of the same X-ray tube using combination of Al and Ag filters and, c) monochromatic radiation using secondary target, in a portable setup with triaxial geometry. The performance of the used setups was compared using model samples made with gold foil standard reference materials of known thicknesses (1, 2 and 2.5 μm). Thickness determination was based on the selective attenuation that the different energies of a given element of an under-layer undergo in the gilded layer. Ideally, as it can be expected from physics fundamentals, monochromatic radiation is needed for improved accuracy. However, considering the difficulties in using monochromatic radiation in portable instrumentation applicable in Cultural Heritage studies, filtered radiation can also be used for reliable results. Moreover, Monte Carlo simulations of the portable setup with conventional planar geometry were performed for comparison and for future application in more complex samples. © 2019 Elsevier Ltd, Financial support for this investigation was provided by Portuguese Foundation for Science and Technology in the funding of LIBPhys-UNL (project — UID/FIS/04559/2013 ). S. Pessanha also acknowledges FCT for the post-doc grant SFRH/BPD/94234/2013 . I. Queralt acknowledges a sabbatical grant from the Ministry of Education of the Spanish Government (Ref. PRX16/00159 ).

This paper reports the results of a multi analytical research undertaken on a mural and on a panel painting altarpiece authored by Jose de Escovar in 1603, one of the most productive and controversial painters working for Evora Archiepiscopate at the end of the 16th century and beginning of the 17th century. The two paintings are among his first documented artworks in the region and the only case where both are still in their original architectural location - the Chapel of the Souls in the main church of Vila Nova da Baronia (30 km away from the city of Evora). Jose de Escovar is a well-known mural painter but not much is still known about his other skills. To better define his craftsmanship, comparison of technical features and painting materials employed on both supports and paint layers was carried out using a multi-analytical setup for in situ analyses and laboratory characterization. The analytical campaign comprised technical photography (UVF-Vis-IR), portable EDXRF, OM, XRD, SEM/EDS, µ-Raman, µ-FT-IR and py-GC/MS. The results showed that although Jose de Escovar was considered a minor painter, he was clearly acquainted with both painting techniques and the use of different materials in accordance with the pictorial specifications and traditions at the time in Europe.

Trace elements are present in minute amounts in the human body but contribute to its proper functioning, by participating in several biological processes. Imbalance of the concentrations of these elements can lead to the development of pathologies, including cancer. As such, the determination of trace element content in tumour tissues and its comparison with normal ones may be helpful for a better understanding of carcinogenesis. In this work, we address the collection and preparation of biological samples for Energy Dispersive X-Ray Fluorescence (EDXRF) analysis, and present a model for the quantification of trace elements, based on the external standard method of quantification. The model was used for the quantification of iron, copper, and zinc in a set of paired samples (normal and tumour tissues). The obtained results show the validity of the method and variations of the elemental concentrations in the different tissues.