X-ray Fluorescence System Research Articles

Investigation of the accuracy of a portable 109Cd XRF system for the measurement of iron in skin

We have previously reported the design of a portable 109Cd x-ray fluorescence (XRF) system to measure iron levels in the skin of patients with either iron overload disease, such as thalassemia, or iron deficiency disease, such as anemia. In phantom studies, the system was found to have a detection limit of 1.35 μg Fe per g of tissue for a dose of 1.1 mSv. However, the system must provide accurate as well as precise measurements of iron levels in the skin in order to be suitable for human studies. The accuracy of the system has been explored using several methods. First, the iron concentrations of ten pigskin samples were assessed using both the portable XRF system and ICP-MS, and the results were compared. Overall, it was found that XRF and ICP-MS reported average values for iron in skin that were comparable to within uncertainties. The mean difference between the two methodologies was not significant, 2.5 ± 4.6 μg Fe per g. On this basis, the system could be considered accurate. However, ICP-MS measurements reported a wider range of values than XRF, with two individual samples having ICP-MS results that were significantly elevated (p < 0.05) compared to XRF. Synchrotron μXRF maps of iron levels in pigskin were acquired on the BioXAS beam line of the Canadian Light Source. The μXRF maps indicated two important features in the distribution of iron in pigskin. First, there were small areas of high iron concentration in the pigskin samples, that were predominantly located in the dermis and hypodermis at depths greater than 0.5 mm. Monte Carlo modelling using the EGS 5 code determined that if these iron ‘hot spots’ were located towards the back of the skin at depths greater than 0.5 mm, they would not be observed by XRF, but would be measured by ICP-MS. These results support a hypothesis that iron levels in the two samples that reported significantly elevated ICP-MS results compared to XRF may have had small blood vessels at the back of the skin. Second, the synchrotron μXRF maps also showed a narrow (approximately 100μm thick) layer of elevated iron at the surface of the skin. Monte Carlo models determined that, as expected, the XRF system was most sensitive to these skin layers. However, the simulations found that the XRF system, when calibrated against homogenous water-based phantoms, was found to accurately measure average iron levels in the skin of normal pigs despite the greater sensitivity to the surface layer. The Monte Carlo results further indicated that with highly elevated skin surface iron levels, the XRF system would not provide a good estimate of average skin iron levels. The XRF estimate could, with correction factors, provide a good estimate of the iron levels in the surface layers of skin. There is limited data on iron distribution in skin, especially under conditions of disease. If iron levels are elevated at the skin surface by diseases including thalassemia and hemochromatosis, this XRF device may prove to be an accurate clinical tool. However, further data are required on skin iron distributions in healthy and iron overload disease before this system can be verified to provide accurate measurements.

The feasibility of K XRF bone lead measurements in mice assessed using 3D-printed phantoms

This article describes the development of a system for in vivo measurements of lead body burden in mice using 109Cd K x-ray fluorescence (XRF). This K XRF system could facilitate early-stage studies on interventions that ameliorate or reverse organ tissue damage from lead poisoning by reducing animal numbers through a cross-sectional study approach. A novel mouse phantom was developed based on a mouse atlas and 3D-printed using PLA plastic with plaster of Paris ’bone’ inserts. PLA plastic was found to be a good surrogate for soft tissue in XRF measurements and the phantoms were found to be good models of mice. As expected, lead detection limits varied with mouse size, mouse orientation, and mouse position with respect to the source and detector. The work suggests that detection limits of 10 to 20 μg Pb per g bone mineral may be possible for a 2 to 3 hour XRF measurement in a single animal, an adequate limit for some pre-clinical studies. The 109Cd K XRF mouse measurement system was also modeled using the Monte Carlo code MCNP. The combination of experiment and modeling found that contrary to expectation, accurate measurements of lead levels in mice required calibration using mouse-specific calibration standards due to the coherent scatter peak normalization failing when small animals are measured. MCNP modeling determined that this was because the coherent scatter signal from soft tissue, which until now has been assumed negligible, becomes significant when compared to the coherent scatter signal in bone in small animals. This may have implications for some human measurements. This work suggests that 109Cd K x-ray fluorescence measurements of lead body burden are precise enough to make the system feasible for small animals if appropriately calibrated. Further work to validate the technology’s measurement accuracy and performance in vivo will be required.

XRF calibration with low-cost samples and implementation for quantification of inorganic elements in lipsticks

In this paper, the preparation of low-cost samples, for the calibration of an energy–dispersive X-ray fluorescence system is presented. The entire procedure is proposed as an undergraduate or postgraduate student laboratory activity, which aims to familiarize students with the procedure of calibration of a spectroscopy-based analytical method through the XRF technique. Furthermore, the use of XRF for the determination of elemental concentrations in samples related to students’ interests, was attempted.

The Distribution Regularity and Flotation Study of Niobium-Bearing Minerals in Baiyun Obo

The characteristics of Baiyun Obo niobium-bearing minerals are complex physicochemical properties that make the beneficiation of niobium minerals extremely difficult. In this paper, X-ray diffraction, X-ray fluorescence and mineral liberation analyzer (MLA) systems were used to study the niobium occurrence state and distribution of niobium-bearing minerals in the samples from Baiyun Obo. The results show that the chemical and mineral compositions of the sample are complex, with a Nb2O5 grading of 0.24%. There are many kinds of niobium minerals, including ilmenorutile, nioboaeschynite-Nd, baotite, latrappite, euxenite-Y, fergusonite and columbite-Mn, and the highest mass fraction of 0.55% is achieved with Nb in nioboaeschynite-Nd, followed by the mass fraction of ilmenorutile (0.33%). All of the niobium-containing minerals demonstrate a low degree of dissociation. Flotation experiments explored the optimal flotation conditions for HOBA (1-hydroxyoctyl-1,1-bisphosphonic acid) as a flotation collector for Baiyun Obo niobium minerals, which is able to increase the grade of Nb2O5 in the concentrate to 1.31%. The optimal use conditions of the reagent are pH 3.5–4.5, and the amount of the collector is 1000 g/t. By further optimizing the beneficiation process and reagent system, ilmenorutile and nioboaeschynite-Nd were significantly enriched in the concentrate, which suggested that HOBA can efficiently increase the grade of Nb2O5 in the concentrate.

A new basic burning raw material for simultaneous stabilization/solidification of PO43−-P and F− in phosphogypsum

Phosphogypsum (PG) contains a lot of soluble phosphate (PO43--P) and fluorine ion (F-), which seriously has hindered the sustainable development of the phosphorous chemical industry. In this study, a new burning raw material (BRM) as an intermediate product in the cement production process was used for PO43--P and F- stabilize in PG. The stabilizing mechanism of PO43--P and F- were investigated by Fourier Transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM), X-ray fluorescence (XRF) and X-ray spectroscopy system (XPS). The effect of PG and BRM weight ratio, solid-to-liquid ratio, reaction time, and reaction temperature on the concentrations of PO43--P and F- were studied. The results showed that the concentration of F- in the PG leaching solution was 8.65 mg/L and the stabilizing efficiency of PO43--P was 99.78%, as well as the pH of the PG leaching solution was 8.12 when the weight ratio of PG and BRM was 100:2, and the solid to liquid ratio was 4:1, reacting for 24 h at the temperature of 30 ℃. PO43--P and F- were mostly solidified as Ca5(PO4)3F, CaPO3(OH), Ca5(PO4)3(OH), Ca2P2O7·2H2O, CaSO4PO3(OH)·4H2O, CaF2, and CaFPO3·2H2O. Leaching test results indicated that the concentrations of PO43--P, F- and heavy metals were less than the integrated wastewater discharge standard (GB8978–1996). This study provides a new harmless treatment method for PG.

Assessment of X-ray fluorescence capabilities for nail and hair matrices through zinc measurement in keratin reference materials

BackgroundNovel and emerging biomarkers of zinc status are being developed to help study and address zinc deficiency around the world. Two potential biomarkers, nail and hair, involve the measurement of zinc from easily accessible keratin-based components of the body. Portable X-ray fluorescence (XRF) is a relatively new approach to the assessment of zinc in nail or hair, and has a number of compelling advantages compared with other techniques. The aim of the current study was to test the ability of XRF to measure zinc in keratinized reference materials (RMs) designed to simulate nail and hair. MethodsFour Keratin Matrix RMs were prepared and characterized for numerous trace elements by the New York State Department of Health’s Wadsworth Center. The Keratin Matrix RMs consisted of powdered samples of caprine (goat) horns pooled from several animals. Concentrations of zinc, as assessed by inductively coupled plasma mass spectrometry (ICP-MS), were similar to what would be expected from human nail or hair tissues. Repeat measurements of the RMs were made using a portable XRF system. The XRF zinc results were compared with the ICP-MS zinc concentrations. Three different approaches to quantifying the zinc content by XRF were performed: (1) zinc signal to total signal ratio, (2) zinc signal to sulfur signal ratio, and (3) system output zinc concentration. ResultsThe portable XRF results from a given RM were found to be consistent across repeat trials under all three approaches to XRF quantitation. Precision, calculated as the relative standard deviation of repeat measurements ranged from an average result of 0.8 % (using the system output zinc concentration method) to 6.1 % (using the zinc signal to sulfur signal ratio method). Measurement of the RMs provided XRF zinc results which scaled well with ICP-MS zinc concentration, particularly when using the XRF zinc to total and system zinc concentration methods. A Bland-Altman plot showed that the XRF system zinc concentration output exceeded the ICP-MS zinc concentration by, on average, 10.2 % ± 1.2 %. ConclusionOverall, both accuracy and precision of measurement were found to be promising for portable XRF, provided appropriate conversions to concentration are introduced. The results of this study indicate that portable XRF is an effective and dependable method of assessing zinc concentration in keratinized tissue RMs. This will have implications for the future use of portable XRF to monitor zinc status in humans through measurements of nail and hair.

Analysis of a wooden statue by non‐destructive X‐ray techniques

AbstractIn this study, the characterization of the “Santa Luzia” statue was carried out through three non‐destructive X‐ray techniques: X‐ray Fluorescence (XRF), Digital Radiography (DR), and Computed Tomography (CT). The wooden statue dates from the 18th century. It was carved in Portugal and is currently located at the Santa Luzia church—one of the oldest churches built in Rio de Janeiro. The portable XRF system used in this study is composed of an Ag target X‐ray tube and an silicon drift detector detector with energy resolution of 122 eV at 5.9 keV. Several spectra were obtained in different regions of the statue. For the DR and CT evaluations, a portable 120 kV X‐ray tube and a 410 × 410 mm a‐Si flat panel detector with a pixel size of 200 μm were used. Individual radiographs of the parts of the statue were acquired and merged into a single image, in order to show its complete radiography. Finally, the CT images of the head of the statue were taken in angular steps of 2 degrees and, after the reconstruction process, the data were analyzed by means of appropriate software. The elements found in the XRF analysis suggest the presence of the pigments lead white, red lead, zinc white, titanium white, vermilion and emerald green. All of them are in accordance with the pigments used by the artists during the statue's historical period. The 3 exceptions were the zinc white and titanium white pigments, which may be an evidence of modern interventions, and the emerald green pigment, which appears to be a repainting of the green region. The radiographic images showed the manufacturing process of the statue, as well as its structural condition. The assembling of wooden blocks, the presence and type of nails and spikes, and regions of different densities were found in the analysis. In the statue's head, the joining of the face with the main part of the statue is clearly visible, and also the hollow glass eye. The CT analysis was able to better detail this section as a spherical cavity in the central part of the head, as well as the presence of a high‐density fragment inside the hole for the fixation of the aureole. The type of glass eye was identified as blown‐glass eye, which is commonly used in devotional statues.

Dual imaging modality of fluorescence and transmission X-rays for gold nanoparticle-injected living mice.

X-ray fluorescence (XRF) imaging for metal nanoparticles (MNPs) is a promising molecular imaging modality that can determine dynamic biodistributions of MNPs. However, it has the limitation that it only provides functional information. In this study, we aim to show the feasibility of acquiring functional and anatomic information on the same platform by demonstrating a dual imaging modality of pinhole XRF and computed tomography (CT) for gold nanoparticle (GNP)-injected living mice. By installing a transmission CT detector in an existing pinhole XRF imaging system using a two-dimensional (2D) cadmium zinc telluride (CZT) gamma camera, XRF and CT images were acquired on the same platform. Due to the optimal X-ray spectra for XRF and CT image acquisition being different, XRF and CT imaging were performed by 140 and 50kV X-rays, respectively. An amount of 40mg GNPs (1.9nm in diameter) suspended in 0.20ml of phosphate-buffered saline were injected into the three BALB/c mice via a tail vein. Then, the kidney and tumor slices of mice were scanned at specific time points within 60min to acquire time-lapse in vivo biodistributions of GNPs. XRF images were directly acquired without image reconstruction using a pinhole collimator and a 2D CZT gamma camera. Subsequently, CT images were acquired by performing CT scans. In order to confirm the validity of the functional information provided by the XRF image, the CT image was fused with the XRF image. After the XRF and CT scan, the mice were euthanized, and major organs (kidneys, tumor, liver, and spleen) were extracted. The ex vivo GNP concentrations of the extracted organs were measured by inductively coupled plasma mass spectrometry (ICP-MS) and L-shell XRF detection system using a silicon drift detector, then compared with the in vivo GNP concentrations measured by the pinhole XRF imaging system. Time-lapse XRF images were directly acquired without rotation and translation of imaging objects within an acquisition time of 2min per slice. Due to the short image acquisition time, the time-lapse in vivo biodistribution of GNPs was acquired in the organs of the mice. CT images were fused with the XRF images and successfully confirmed the validity of the XRF images. The difference in ex vivo GNP concentrations measured by the L-shell XRF detection system and ICP-MS was 0.0005-0.02% by the weight of gold (wt%). Notably, the in vivo and ex vivo GNP concentrations in the kidneys of three mice were comparable with a difference of 0.01-0.08wt%. A dual imaging modality of pinhole XRF and CT imaging system and L-shell XRF detection system were successfully developed. The developed systems are a promising modality for in vivo imaging and ex vivo quantification for preclinical studies using MNPs. In addition, we discussed further improvements for the routine preclinical applications of the systems.

Evaluation of 20 Elements in Soils and Sediments by ED-XRF of Monochromatic Excitation

There is an urgent need for the accurate analysis of heavy metal contamination in the field of ecology and environmental sciences, especially in the case of trace heavy metals, such as cadmium. Using doubly curved crystals (DCC) to achieve the monochromatic X-ray excitation of the sample to be measured and a silicon drift detector (SDD) to collect the fluorescence of the sample elements, combined with an algorithm analysis of the fundamental parameters (FP), the monochromatic energy-dispersive X-ray fluorescence (MED-XRF) system significantly improved the detection limits of the target elements. The detection limits, precision, and accuracy of the MED-XRF acquisition for 20 elements, including cadmium, lead, and arsenic, were evaluated and compared with the Determination of Inorganic Elements in Soil and Sediment Wavelength-Dispersive X-ray Fluorescence Spectrometry report and tested on the actual samples. The test results showed that the detection limit of the inorganic elements in soil and sediment determined by MED-XRF was mostly better than the industry standard, especially the detection limit of Cd, which was 0.04 mg/kg. The accuracy and correctness fully met the requirements for daily laboratory testing and, as a quality control tool, the actual sample testing and laboratory ICP-MS results were consistent. The research conducted in this project constituted a useful attempt to expand and improve the analytical methods for inorganic elements in soil and sediment, showing that MED-XRF is superior to conventional ED-XRF and WD-XRF and is the current new method of analysis for a low content of Cd in soil. MED-XRF offers a very important contribution to research on soil census, conservation, the rational use of agricultural land, and soil restoration and improvement, and provides strong support for field testing.

Evaluation of different analytical approaches using total reflection X-ray fluorescence systems for multielemental analysis of human tissues with different adipose content

Elemental content plays an important role in biological processes, and so, the multielemental analysis of human tissue samples is required in biomedical research. Still, the small amount of available biological samples and the adipose content of the samples can be major setbacks for the accurate determination of elemental content.In this study, we explored the potential of several analytical approaches combined with total reflection X-ray fluorescence spectrometry (TXRF) for multielemental analysis of human tissues with different adipose content (colon, heart, liver, lung, muscle, intestine, skin, stomach, uterus, bladder and aorta). The capabilities and limitations of different sample treatment procedures (suspension and acidic digestion) and two TXRF systems with different anode configurations (Mo and W X-ray tubes) have been evaluated for such purpose. Results showed that for tissues with a higher fat content (e.g., skin, and intestine) the best strategy was the acidic digestion of the sample before TXRF analysis. However, for other tissues, acceptable results were obtained by suspending 20 mg of powdered material in 1 mL of 2 M nitric acid. A further enhancement of the limits of detection and accuracy of the results was achieved if using Mo-TXRF systems, especially for the determination of low Z elements (e.g., K, and Ca) and of elements present at low concentrations (e.g., Cu) in the human tissues.Finally, results by TXRF analysis were compared with those obtained with μ-EDXRF and ICP-OES, and a good agreement was obtained.

In vivo quantification of strontium in bone among adults using portable x-ray fluorescence

Background and objectiveBone strontium (Sr) is a reliable biomarker for studying related bone health outcomes and the effectiveness of Sr supplements in osteoporosis disease treatment. In this study, we evaluated the sensitivity of portable x-ray fluorescence (XRF) technology for in vivo bone Sr quantification among adults. Materials and methodsSr-doped bone-equivalent phantoms were used for system calibration. Using the portable XRF, we measured bone Sr levels in vivo in mid-tibia bone in 76 adults, 38–95 years of age, living in Indiana, US; we also analyzed bone data of 29 adults, 53–82 years of age, living in Shanghai, China. The same portable XRF device and system settings were used in measuring their mid-tibia bone. We compared bone Sr concentrations by sex, age, and recruitment site. We also used multiple linear regression model to estimate the association of age with bone Sr concentration, adjusting for sex and recruitment site. ResultsThe uncertainty of in vivo individual measurement increased with higher soft tissue thickness overlying bone, and it ranged from 1.0 ug/g dry bone (ppm) to 2.4 ppm with thickness ranging from 2 to 7 mm, with a measurement time of 5 min. Geometric mean (95% confidence interval (CI)) of the bone Sr concentration was 79.1 (70.1, 89.3) ppm. After adjustment for recruitment site and sex, an increase in five years of age was associated with a 8.9% (95% CI: 2.5%, 15.6%) increase in geometric mean bone Sr concentration. Discussion and conclusionSr concentrations were consistently well above detection limits of the portable XRF, and exhibited an expected increase with age. These data suggest that the portable XRF can be a valuable technology to quantify Sr concentration in bone, and in the study of Sr-related health outcomes among adults, such as bone mineral density (BMD) and bone fracture risk.

Determining the sensitivity curve of Energy Dispersive X-ray Fluorescence and PIXE systems

The study of thin and thick materials every time is a challenge in X-ray analysis. The calculation of the sensitivity curve of Energy Dispersive X-ray Fluorescence (ED-XRF) and Particle Induced X-ray Emission (PIXE) systems allows for better quantitative analysis and also allows the determination of the concentration of a chemical element in a given thin sample from its intensity. The sensitivity curve can be found through the analysis of elemental standards, samples with well-defined superficial densities (μg/cm 2) that allow the calculation of the sensitivity of the system to the elements present in the standards. From these standard values, it is possible to fit a curve and find the sensitivity equation as a function of the atomic number. After that, the sensitivity curve which will be used to determine the elemental composition can help to calculate the concentration of any of the chemical elements of the periodic table present in a sample. Also, PIXE and ED-XRF are known to have a different sensibility and limits of detection (LOD) to determine elemental concentrations. In this article, the sensitivities of a portable ED-XRF and a PIXE system were calculated and compared. Altogether, the results showed that, for the experimental setups used, ED-XRF has better sensitivity associated with the chemical elements of intermediate atomic numbers, while PIXE’s functions describe better the sensitivities to the lighter and heavier chemical elements of the periodic table.

Preliminary study on trace elements distribution and electron density variation in canine mammary tissues using a synchrotron-based micro X-ray fluorescence system

Mammary neoplasms are the most common in female dogs, with high malignancy rates. Despite sharing many similarities with human breast tissues, the prevalence of this type of cancer in dogs are nearly three times higher. Taking that into account, this study aims to present preliminary results about chemical and structural changes occurring in samples of canine breast tumors. For this, we analyzed seven samples including normal, benign and malignant tissues, using micro X-ray fluorescence (μ-XRF) and Compton scattering technique. Our goal was to respectively map the spatial distribution of Fe, Cu and Zn and to determine the electron densities in selected regions of the samples. Results showed that Cu and Zn distributions were spatially correlated in normal tissues, with lower intensities in adipose regions and higher in the fibrous ones. Regarding benign neoplasms, both samples exhibited an increase in Cu intensity over the tumor area, however in different proportions. For the malignant ones, the presence of Fe was observed mostly in the tumor-adjacent regions. The electron density values obtained allowed to differentiate tissue structures, with generally higher density in tumorous regions and lower in adipose tissues.

Application of automated and robotically deployed in situ X‐ray fluorescence analysis for nuclear waste management

AbstractLaboratory and synchrotron X‐ray fluorescence (XRF) analysis has both served as mainstay rapid and quantitative elemental analysis techniques for decades, attaining parts per million sensitivities for the majority of elements. Formerly, XRF was the reserve of large X‐ray generating systems and national facilities. More recently, developments in miniaturized X‐ray generators and detectors have allowed for this nondestructive technique to be utilized for portable and in situ elemental characterization of materials, away from the confines of the laboratory. When combined with a robotic manipulator, these usually handheld systems present a powerful method for autonomous assessments of material composition for a wide range of nuclear characterization and decommissioning scenarios. In this study, we present a proof‐of‐concept XRF system integrated with a robotic manipulator to autonomously identify a suite of nuclear relevant materials. Such remotely deployable noncontact tools are crucial for use within hazardous environments where it may not be possible, for physical and safety reasons, for a human operator to manually undertake characterization tasks. It is envisaged that this robotically deployed XRF system will comprise part of the wider autonomous characterization “toolkit”; capable of extensive large‐area mapping alongside targeted compositional “point analysis.” The system was demonstrated to rapidly and repeatably derive accurate and precise compositional information of different test materials, autonomously on both flat and complex, object‐rich surfaces.

Investigating methods of normalization for X-ray fluorescence measurements of zinc in nail clippings using the TOPAS Monte Carlo code

Development of portable X-ray fluorescence devices has made it easier to quickly assess trace elements such as zinc in human tissue. A TOPAS Monte Carlo code was used to investigate the use of a portable X-ray fluorescence system for detecting zinc in nail clippings. The obtained energy spectra from different nail thicknesses were analyzed and three different normalization techniques (coherent, Compton, and entire spectrum) were introduced. The simulation results suggested that coherent normalization can be a particularly robust normalization procedure.

Low-Cost Multispectral System Design for Pigment Analysis in Works of Art.

To better understand and preserve works of art, knowledge is needed about the pigments used to create the artwork. Various noninvasive techniques have been used previously to create pigment maps, such as combining X-ray fluorescence and hyperspectral imaging data. Unfortunately, most museums have limited funding for the expense of specialized research equipment, such as hyperspectral reflectance imaging systems. However, many museums have hand-held point X-ray fluorescence systems attached to motorized easels for scanning artwork. To assist museums in acquiring data that can produce similar results to that of HSI systems, while minimizing equipment costs, this study designed and modeled a prototype system to demonstrate the expected performance of a low-cost multispectral system that can be attached to existing motorized easels. We show that multispectral systems with a well-chosen set of spectral bands can often produce classification maps with value on par with hyperspectral systems. This study analyzed the potential for capturing data with a point scanning system through predefined filters. By applying the system and noise modeling parameters to HSI data captured from a 14th-Century illumination, the study reveals that the proposed multispectral imaging system is a viable option for this need.

Analysis of painting Victor Meirelles’ “Passagem de Humaitá” by XRF

Analysis of historical artifacts, it's a multidisciplinary field of research known as archaeometry, has expanded greatly in recent years. One of the reasons for this expansion was the great effort of physicists and engineers, who focused on the development of portable instruments, that allow analyses in situ and non-destructive of these artifacts. The X-Ray Fluorescence (XRF) is techniques of the most used in this field of study. In this work the XRF was used to analysis the artwork "Passagem de Humaitá", by the Brazilian painter Victor Meirelles, dated 1872. The painting, which has dimensions of 268 cm x 405 cm, is exposed at National Historical Museum located in Rio de Janeiro. The analyses were carried out in situ with portable XRF system model TRACER IV from Bruker, which has Rh anode and can operate with maximum voltage and current of 40 kV and 200 μA. Spectra of more than 80 points of the painting were obtained, with the tube operating at voltage of 40 kV and a current of 10 μA, and the spectra were collected during 60 seconds. The results allowed to conclude that the painter used pigments such as vermilion and/or cinnabar [HgS], calcite [CaCO3], zinc white [ZnO], lead white [(PbCO3)2·Pb(OH)2], red ocher [Fe2O3], brown umbra [Fe2O3.MnO2].

Advantages and pitfalls of the use of mobile Raman and XRF systems applied on cultural heritage objects in Tuscany (Italy)

Mobile Raman and XRF systems are particularly suitable for the study of cultural heritage objects, allowing in situ, nondestructive analysis on a large variety of materials. Nowadays, thanks to technological developments, the size of the new generation of mobile instruments is reduced. Moreover, operation of the instrumentation is straightforward, as most instrumental settings and data interpretation are automated. However, automated data processing should be evaluated carefully and the risks of incorrect data collection and/or interpretation must be considered and prevented. Therefore, the aim of this research is to start a discussion about some of the challenging aspects and pitfalls, which can be encountered when using mobile techniques. Data collection and interpretation are examined when dealing with works of art. Those aspects are highlighted based on a measuring campaign carried out in Tuscany (Italy) in three different contexts: an archaeological excavation in the Late Roman Villa dell’Oratorio (Capraia-Limite sull’Arno, Florence), the analysis of a mosaic at the facade of the Pisa Cathedral and studies inside the Museo dell’Opera del Duomo (Pisa), where some outdoor statues are exhibited. Measurements were acquired with two state-of-the-art mobile Raman and one handheld X-Ray fluorescence (XRF) systems.

A Study of Preparing Samples of Hydroxyapatite with Different Densities Using Charcoal Powder

The powder of hydroxyapatite with the chemical formula Ca10 (PO4) 6 (OH) 2 was prepared locally from cow bones in the hexagonal crystal phase, and this was confirmed through the X-ray diffraction system. The proportions that formed the prepared hydroxyapatite were confirmed through the X-ray fluorescence system and found the ratio of calcium oxide to phosphorous oxide is 1.718. The hexagonal phase of the prepared hydroxyapatite was also stabilized ( fixed ) for the samples before and after the heat treatment. Some physical and mechanical properties were also conducted for the prepared samples. It was found that it is possible to prepare samples of different densities by adding different proportions of carbon (charcoal) percentage to the prepared hydroxyapatite.

Fundamental research for a new confocal line X‐ray spectrometer

Confocal X‐ray fluorescence (XRF) spectrometry can be used to perform three‐dimensional elemental analysis, which is impossible using general micro XRF spectrometry without any collimating optics in the detection channel. In this study, we designed, for the first time, a new confocal line XRF (C‐L‐XRF) system that can obtain elemental information of a larger area and higher intensity in XRF analysis than conventional confocal point XRF (C‐P‐XRF) analysis. We evaluate the basic performance of C‐L‐XRF, such as XRF intensity and horizontal and depth spatial resolutions. We identified that the spatial resolution of C‐L‐XRF in the horizontal and depth directions is approximately 2.9 and 2.6 times those of conventional C‐P‐XRF. However, it is possible to obtain an XRF intensity that is approximately 33 times higher than C‐P‐XRF intensity. C‐L‐XRF is expected to be effective for analyzing wide‐area samples such as layered samples.