Energy Dispersive X-ray Fluorescence Spectrometry Research Articles

Morphology and Structure Characteristics of the Rare Black-Glazed Porcelains Excavated from the Jian Kiln Site of Song Dynasty

Jian tea bowls are greatly appreciated not only due to their thick and lustrous black glazes, but also their exquisite streaked and mottled patterns. Researches on the firing process and colouring mechanism of typical hare’s fur and oil spot Jian glazes have continuously been carried out in the past decades; however, there are few reports about other scarce types of black-glazed porcelains excavated from the Jian kiln site. In this work, we report on a multi-technique analysis of the surface and cross-sectional structure, phase, morphology and chemical composition of three rare types of Jian tea bowls (tea-dust-glazed ware, grey-glazed ware and pearl-glazed ware) combining optical and spectroscopic methods such as optical coherence tomography (OCT), optical microscopy (OM), Portable energy dispersive X-ray fluorescence spectrometry (XRF), laser-Raman spectroscopy (LRS) and scanning electron microscopy coupled with an X-ray energy dispersive spectrometer (SEM-EDS). Results revealed that the tea dust glaze was one high-temperature iron-based crystalline glaze, and its glaze was characterized by a transparent glass matrix; irregular pits completely or partially filled by TiO2; and that ε-Fe2O3 and residual quartz were randomly distributed all over the surface, which produced the appearance of tea-dust. The grey-glazed porcelain was fired at a lower temperature in the dragon kiln than that of the traditional hare’s fur and oil spot samples, its glaze contained some residual quartz, and anorthite crystals showed a serried distribution along the thickness. The pearl-glazed porcelain was fired through a secondary glazing process via artificial stippling quartz powder. This work provides guidance for the firing process of three rare types of Jian wares and has not only scientific but also cultural profound significance, which reveals the features of their historical heritage.

Microstructure and Strength Parameters of Cement-Stabilized Loess

In this study, cement was used as a component to provide a stabilizing effect in order to evaluate the hardness and stability of loess soil. To evaluate the strength properties of loess soil reinforced with cement, samples with four distinct cement concentrations (3%, 5%, 7%, and 9%) and three distinct curing durations (7, 14, and 28 days) were generated. During a series of tests, the flexural strength, direct shear strength, indirect tensile strength, and unconfined compressive strength were determined. An appropriate cement dosage was found, in addition to a durability index that could be used to quantify the effect of water absorption investigations on cement-stabilized loess. Both of these discoveries were made simultaneously. Scanning electron microscopy (SEM) and energy dispersive X-ray fluorescence spectrometry (XRF) examinations were carried out so that the fundamental mechanics of the materials could be comprehended. The results show that the cohesion of cement-stabilized loess is much more sensitive to structure than the friction angle of the material. The increase in shear strength after remoulding is due to cohesion. The SEM study showed that the cement interacted with the loess particles to produce a thick cement network that successfully covered the voids and boosted the mixture’s strength parameters. The 28-days UCS for the samples containing 7% cement was the greatest, at 3.5 MPa, while the UCS for those containing 9% cement was 4.78 MPa. The highest flexural tensile strength of 1.98 N/mm2 was determined after 28 days. The tensile strength after 7 days in samples containing 3%, 5%, 7%, and 9% cement reached a maximum force of 0.15 MPa, 0.23 MPa, 0.27 MPa, and 0.37 MPa, respectively, and increased with each passing day. To achieve the desired level of strength, it is necessary to adjust the proportion of cement. In addition, as the curing period progressed, we observed an increase in the resistance and stiffness of the cement-stabilized loess due to the interactions that take place between the structure and the mineral composition. It is believed that this event was caused by naturally occurring cementation. As a consequence of this reaction, the production of new cementitious materials takes place. The cation exchange that causes the hydration and pozzolanic reaction that leads to the creation of aggregates and interparticle flocculation is responsible for their production. These findings suggest that cement may be utilised as a simple and effective method of loess stabilization, ultimately resulting in improved performance of the loess. Therefore, this study revealed that cement may considerably enhance the microstructure and strength parameters of loess. This research provides important information on cement-stabilized loess that has ramifications for geotechnical investigation, construction, research, and testing to achieve a successful project.

Chamotte Clay: A Natural Adsorbent for Separation and Preconcentration of Aluminium

The adsorption behavior of aluminium ions on chamotte clay has been studied in this study. Chamotte clay has been used for the first time for determination of trace levels of aluminium in aqueous solutions. Quantitative adsorption and recovery of aluminium were both rapid and reached an equilibrium in 30 minutes. Aluminium was detected based on the formation of the highly fluorescent Al(III)-morin complex. Two linear calibration graphs were obtained in the range of 0.5-10 µg L-1 and 10-100 µg L-1 with the detection limits of 0.12 µg L-1 and 1.12 µg L-1, respectively. Chamotte clay was characterized by scanning electron microscope coupled with energy-dispersive X-ray spectroscopy, energy dispersive X-ray fluorescence and X-ray photoelectron spectroscopy techniques. Different isotherm models were evaluated and the results showed that the adsorption study was fitted to Freundlich isotherm and a favorable and multilayer adsorption of aluminium was occurred on the heterogeneous surface of the chamotte clay. Thermodynamic and kinetic parameters of aluminium adsorption were also investigated. Various experimental parameters were optimized and the method has been applied to tap and bottled drinking water samples and quantitative recoveries were obtained. The results demonstrated that the chamotte clay, as a natural clay, was expected to be a promising adsorbent for the determination and preconcentration of the trace levels of analyte in real samples.

A study by portable X-ray fluorescence (pXRF) of the painting “Still Life with Vase, Plate and Flowers” (1886–1888)

Portable energy-dispersive X-ray fluorescence spectroscopy (pXRF) was employed in the characterization of the pigments present in the painting “Still Life with Vase, Plate and Flowers”, of unknown authorship, but previously attributed to Vincent van Gogh, belonging to the collection of the São Paulo Museum of Art (MASP). In situ pXRF measurements were carried out by means of a portable system in order to provide the museum with a scientific documentation about the materials in the painting. Spectra were taken at different color regions and different hues in the pictorial layer. Some of the materials identified in the painting were chalk and/or gypsum, lithopone, lead white, zinc white, bone black, barium yellow, chrome yellow, yellow ochre, chrome green, Prussian blue, cobalt blue, vermilion and red earth. Besides that, it was possible to suggest the use of a lake pigment. The pigments whose use is suggested by this work are in total agreement with those available to European artists in the end of the 19th century.

Highlighting the Characteristics of Roman Mortars from Ovidiu’s Quadriburgium Archaeological Site, Romania

This study examines the mortar materials used in the construction of the walls at the Archaeological Roman Fortification site (Ovidiu, Romania) on the shore of Siutghiol Lake. Several analyses were conducted to determine the mortars’ basic physical properties, mineralogical composition, and microstructural characteristics in order to describe the mortars used in the construction of the Roman fortress. The investigation utilized X-ray diffraction (XRD), energy dispersive X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM-EDAX), and differential thermal analysis (TGA-DTA). The results indicated that siliceous aggregates and lime binders were used in the production of the studied mortars, the structure was constructed in the sixth century, and the raw materials used to construct the site are of local origin. Using the methods mentioned above, there is the possibility of recreating the fortification’s mortar formula using contemporary materials and recommending intervention materials for the preservation of the archaeology of the Roman Fortification. Furthermore, this study opens up many other research opportunities regarding the reuse of mortars extracted from archaeological sites in the rehabilitation process by integrating them into new mortar recipes that can then be tested to compare the results with those obtained from standardized recipes.

Levels of elements in selected food substances that support usage in the management and treatment of erectile dysfunction.

The use of fruits and vegetables for the management and treatment of erectile dysfunction has gained popularity due to the cheaper cost, accessibility and perceived absence of side effects. Much of the work done on plant-based aphrodisiacs has focused on the phytochemistry of secondary metabolites. This work sought to analyze selected fruits and vegetables that are commonly used in the management of erectile dysfunction in Ghana and quantify the levels of some micro- and macro-elements necessary for good penile health in order to determine the usefulness or otherwise of the selected produce. Energy-dispersive X-ray fluorescence spectroscopy was used to detect and quantify the levels of potassium (K), calcium (Ca), selenium (Se), magnesium (Mg), iron (Fe), and zinc (Zn) in carrot roots, cucumber fruit, garlic bulb, ginger rhizome, nutmeg fruit, sweet potato tuber, tiger nut tuber and watermelon fruit. The analysis revealed the presence of K, Ca, Mg, Fe and Zn. Levels of Se were below detection. The concentration of K was the highest in each of the food substances. However, in terms of recommended daily allowance, Mg had the highest contribution. Cucumber fruit and the rind of watermelon fruit had the highest levels of micro- and macro-elements implicated in erectile dysfunction. The potential use of these foods to treat and manage erectile dysfunction may not only be due to the presence of phytochemicals alone but also the presence of significant levels of micro- and macro-elements required for good penile health.

Genesis of the Body Color of Brazilian Gem-Quality Yellow-Green Opal

The chromaticity characterization and influencing factors of the body color of 28 yellow-green opals were studied through Fourier transform infrared spectrum (FTIR), energy-dispersive X-ray fluorescence spectroscopy (ED-XRF), ultraviolet-visible spectroscopy (UV-vis) and X-Rite SP62 spectrophotometer. It was found that the hue h° and the iron content of the yellow-green opal were highly negatively correlated, the chroma C* and the sum of nickel and iron content were significantly positively correlated, and the lightness L* was significantly negatively correlated with the chromium content. The body color of light green opal is mainly caused by nickel. The iron content will make the color yellow, and the chromium content will darken the green. With the increase of Fe content, the lowest absorption value of UV-vis absorption at 500–650 nm moves towards the long wave direction, and the hue h° decreases. With the increase of the total content of Ni and Fe, the 650 nm absorption peak area and the chroma C* increase. Under CIE D65 standard light source and N9.5 Munsell neutral background, using K-Means clustering method, 28 yellow-green opal body colors were divided into three grades: (1) Fancy Intense, (2) Fancy Deep and (3) Fancy.

Assessment of Heavy Metals Concentrations in Some Irrigated Soils of Dadin-Kowa Dam, Gombe State, Nigeria

This study assessed heavy metals concentration in some irrigated soils of Dadin Kowa Dam, Gombe State Nigeria. The soils were collected along transect lines (different sampling points) within the farms and samples were taken to the laboratory for analysis. The analysis was conducted using (Thermo Fisher Scientific) Energy Dispersive X-ray Fluorescence Spectroscopy. The results give the following metals with their mean concentrations: Mo (8.200 and 8.926), Zr (432.990 and 440.236), Sr (204.358 and 87.142), Rb (47.642 and 42.533), Zn (44.165 and NA), Cu (42.161 and NA), Fe (43090.640 and 24846.236), Mn, (992.881 and 397.248), Cr (140.456 and 88.054), V (56.842 and 27.159), Ti (2403.982 and 1421.486), Ca (3344.789 and 982.722), K (4706.758 and 3172. 047), S (466.152 and 310.510), Ba (933795.090 and 959675.238) and Nb (26.285 and 24.964) were obtained from the onion and cabbage farmssoils samples respectively (Values in part per millions (ppm)). The degree of pollution of the soils studied were ascertained and compared with literature toxicity data. Other pollution indices like Enrichment factor, Clarke ratio, Coefficient of variation, Contamination factor, Metal Pollution Index and Geo- Accumulation Index were assessed also and found out that the contamination level for the soils is tolerable for irrigation. At α = 0.01 significant level, positive correlation exists between Fe and Cu, Zn and Ca while Zn and Rb; Ca and Rb have significantly negative correlation between them. By implications, these results showed that the complexes of some elements within the soil strata could influence the presence of other given elements. Therefore, Dam irrigation area soils studied showed relatively low state of pollution for the elements determined.

A Non-Invasive In Situ Spectroscopic Analysis of Cinnabar Minerals to Assist Provenance Studies of Archaeological Pigments

This study presents a non-invasive in situ methodology based on the use of portable elemental (energy dispersive X-ray fluorescence spectroscopy, EDXRF) and molecular (Raman spectroscopy) spectroscopic-based instrumentation as a tool to obtain preliminary information to assist subsequent provenance studies of archaeological cinnabar pigments in the laboratory. In this work, six cinnabar mineral ores, extracted from the Almadén mining district and an original raw pigment coming from the Archaeological Park of Pompeii have been analyzed. As the detection capacities and spectral resolution of the portable instruments are usually poorer than the equivalent benchtop equipment, a comparative study of the in-situ and laboratory results was conducted. Afterward, chemometric data treatment was performed considering both the molecular and elemental information. According to the elemental results, it was not possible to find a strong concordance between the cinnabar ores and the pigment from Pompeii, suggesting the need for additional methodologies in the laboratory (isotope ratio analysis) to complete a proper provenance study. However, this approach was useful to classify the ores according to their mineralogical differences. Therefore, this methodology could be proposed as a useful tool to conduct a representative sampling of the cinnabar mineral ores to be considered in a provenance study of archaeological cinnabar pigments.

Study of the Materials and Techniques of a Rare Papier-Mâché Mushroom Model Crafted in H. Arnoldi Factory.

The Natural History and Science Museum of the University of Porto houses a collection of 45 models of fungi in papier-mâché from the 19th-century, which were used at the university until 2015 as didactic models. For the first time, the materials and techniques used in the production of a Boletus edulis model were studied (vernacular name: cep, porcini). These sculptures, made to life-size scale, are painted in colors similar to those of the represented species (white, brown, and light brown). They are fixed to a rectangular base, which is painted black, and to which moss has been pasted. To fully characterize each color, at the molecular level, a multi-analytical approach was used, combining energy-dispersive x-ray fluorescence spectroscopy (micro-XRF) with fingerprinting techniques of Raman microscopy (microRaman and handheld Raman) spectroscopy and microFourier transform infrared spectroscopy (microFTIR). The papier-mâché was prepared with a groundwood paper to which kaolin and a quartz-based material have been added to reinforce the structure. Raman microscopy also identified carbon black in it, which is possibly responsible for its grey color. The white color was unequivocally identified as lithopone by microRaman. This white paint was prepared in a proteinaceous tempera, with calcium carbonate having been identified as filler (by microFTIR). In the brown color, iron was identified by microXRF, pointing to the use of ocher, which was not possible to identify by microRaman and microFTIR. Regarding the black rectangular base, the moss was fixed using a collagen-based glue. The binding medium in this black is possibly a mixture of drying oil and protein. Again, XRF detected iron as the main element, but it was not possible to acquire a Raman spectrum due to the high fluorescence of the binder/varnish. Others, such as the writing inks, will also be discussed. The colors identified are in line with the best materials available for use by artists of that time. This new knowledge is fundamental to informing the choice of the best conservation strategies for the preservation of these extraordinary models.

Critical Analysis of the Materials Used by the Venetian Artist Guido Cadorin (1892–1976) during the Mid-20th Century, Using a Multi-Analytical Approach

The present study sought to expand on and confirm the already available information on the painting materials used by the Venetian artist Guido Cadorin (1892–1976). A multi-analytical approach was employed in the study of six tempera grassa easel paintings and one casein tempera on a panel signed by the artist and belonging to the International Gallery of Modern Art Ca’ Pesaro in Venice, Italy, which dated from 1921 to 1951. The aim of the research was to identify the painting materials, observe the evolution of the color palette through time and assess the state of conservation. Non-invasive imaging and/or spectroscopic techniques were employed, such as hyperspectral imaging spectroscopy (HSI) and Raman spectroscopy. Microsamples were also collected from the edges and detached areas of the canvases that were studied through three non-destructive techniques, namely optical microscopy (OM), energy dispersive x-ray fluorescence spectrometry (EDXRF) and attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), and one destructive technique, namely gas chromatography-mass spectrometry (GC/MS). The results allowed the inference of the color palette used to render the artist’s paints, composition of the preparation layer, and characterization of the binding media and varnish layers. Moreover, the state of conservation of the artworks was determined. Thus, the outcome of this research enriches the painter’s profile and might aid the International Gallery of Modern Art Ca’ Pesaro in Venice, Italy in the planning of future conservation treatments in accordance with the guidelines of good practices in art conservation.

Evaluating possible prehistoric cave art in the central Mediterranean: Analyses of pigment traces and identification of taphonomic processes at Għar Ħasan, Malta

The archaeology of the Maltese Islands, particularly the megalithic ‘temple’ structures and underground mass burial sites (hypogea) of the ‘Temple Period’ (ca. 3800 – 2300 BCE), has been the subject of considerable interest. Less is known about the prehistoric use of caves. In particular reports of prehistoric cave art at Għar Ħasan (Hasan’s Cave) have remained controversial, and have been argued to reflect an otherwise unknown pre-Neolithic occupation on the islands.Here, we report a reinvestigation of Għar Ħasan. To distinguish graffiti that have accumulated over the last century and possible older rock art, a range of non-invasive methods were used to determine the chemical properties and colour spectrum of the pigment traces: portable energy-dispersive X-ray fluorescence spectrometry (p-ED-XRF) and visible (VIS) and near-infrared (NIR) spectroscopy. In addition, pigment traces were analyzed with digital microscopy and image enhancement techniques (DStretch).Most of the previously reported cave paintings were shown to have been produced in the last century. One key panel may be older, but vandalism and other destructive processes make a definitive assessment challenging. While we therefore consider the evidence for ‘Palaeolithic’ cave art at Għar Ħasan to be inconclusive, our study also identified complex taphonomic processes that pose severe limitations on the identification of pigment via p-ED-XRF and spectroscopy and can inform and guide future initiatives for rock art conservation.

Antifungal activity of silver nanoparticles prepared using Aloe vera extract against Candida albicans.

Resistance to antifungal agents is a serious public health concern that has not been investigated enough because most studies on antimicrobials are dedicated to antibacterial resistance. This study aimed to synthesize silver nanoparticles (AgNPs) using Aloe vera extract, and to assess its antifungal activity against Candida albicans. Silver nanoparticles were synthesized by reducing Ag nitrate with aqueous A. vera extracts. Physicochemical properties of synthesized AgNPs were determined by ultraviolet-visible spectrophotometry, photon cross-correlation spectroscopy, energy-dispersive X-ray fluorescence spectrometry, X-ray diffraction analysis, and Fourier-transform infrared spectroscopy. An antifungal investigation was performed against four clinical C. albicans (C1, C2, C3, and C4) and a reference strain, C. albicans ATCC 10321. Cubic AgNPs with a mean X50 hydrodynamic diameter of 80.31 ± 10.03 nm were successfully synthesized. These AgNPs exhibited maximum absorbance at 429.83 nm, and X-ray fluorescence (XRF) confirmed the presence of Ag in AgNPs solution by a characteristic peak in the spectrum at the Ag Kα line of 22.105 keV. Infrared spectra for AgNPs and A. vera extract indicated that the compounds present in the extract play an essential role in the coating/capping of synthesized AgNPs. Different concentrations (200, 100, 50, 25, 10, and 5 μg/mL) of AgNPs were tested. The antifungal activity was shown to be dose-dependent with inhibition zones ranging from 10 mm to 22 mm against C. albicans ATCC 10231, 0 mm to 15 mm against C1, 0 mm to 16 mm against C2 and C3, and 0 mm to 14 mm for C4. Minimum inhibitory concentration ranged from 16 μg/mL to 32 μg/mL against clinical C. albicans (C1, C2, C3, and C4) and was 4 μg/mL against C. albicans ATCC 10231. This study showed the ability of A. vera to serve as an efficient reducing agent for the biogenic synthesis of AgNPs with excellent antifungal activity.

CONTRIBUTIONS TO THE STUDY OF HEAVY METALS POLLUTING FROM THE ENVIRONMENT, BY ATOMIC SPECTROMETRY

"In this scientific work are presented a part of the results included in the thesis entitled "Contributions to the study of heavy polluting elements from the environment by atomic spectrometry" which includes the innovative contributions to the study of the distribution of heavy metals in acacia leaves collected from Dâmbovița county and neighboring counties and the distribution of heavy metals from surface and deep soil collected from the main oil parks in Dâmbovița county. In the analysis of heavy metal concentrations in the studied samples, the spectrometric techniques were used: Atomic Absorption Spectrometry (AAS) and Energy Dispersive X-Ray Fluorescence Spectrometry (EDXRF), which were successfully optimized and provided valuable information used in following studies, to assess degree of heavy metal pollution of the environment. These methods were used in a complementary way with the biomonitoring technique in order to have as complete information as possible of the elemental composition of the analyzed samples."

Nickel Nanoparticles Anchored on Bentonite Clay for Methane Decomposition with Ordered Carbon as a Product

Catalysts were synthesized with Ni and bentonite clay, without previous treatment, through wet impregnation with 5, 10 and 20% of Ni (m/m). They were characterized by energy dispersive X-ray fluorescence spectrometry (EDX), X-ray diffraction (XRD), temperature-programmed reduction (TPR), thermogravimetric analysis (TGA), adsorption and desorption of N2 at 77 K, and transmission electron microscopy (TEM). The catalytic activity in relation to the methane conversion reaction was evaluated at 500 °C for 0.5 h. The addition of 10 and 20% of nickel to the clay led to a disordered bentonite structure, characterized by the disappearance of the 001 reflection on the X-ray diffractograms, with a consequent increase in the interaction between nickel oxide and clay (TPR). All catalysts synthesized showed catalytic activity in relation to the conversion of methane to form ordered carbon. The catalyst with 20% of nickel had the highest activity, with 74% of methane conversion.

Assessment of heavy metals in fish and sediments from river Mtakuja in the vicinity of a gold mine in Tanzania

Concentrations of heavy metals namely Cr, Fe, Cu, Zn, As, Cd and Pb in African Sharptooth Catfish (clarias gariepinus) and sediment from river Mtakuja Tanzania were analyzed using the Energy Dispersive X-ray Fluorescence spectrometry technique. 32 samples from fish and sediment were investigated. The results show that the concentration of heavy metals was higher in upstream areas than in the downstream area. The concentration of Fe of 428.5 mg/kg in catfish from the upstream area was about 2 times 243.8 mg/kg obtained from the same fish in the downstream area. Similar cases observed for sediments with Fe concentration of 127626.9 mg/kg from upstream that was about 6 times higher than that of 21460.3 mg/kg from downstream area. The concentration of 44.8 mg/kg for Cu in the upstream area sediment was also about 2 times higher than 23.2 mg/kg in the downstream area sediment, while for as the concentration of 13.2 mg/kg was measured in the upstream, which is which is more than 5 times 2.5 mg/kg measured in downstream. The concentration of Cr in the catfish was 17.6 mg/kg which is higher than the permissible limit values of 0.8 mg/kg set by the European Commission (EC), 0.2 mg/kg set by the Food and Agricultural Organization (FAO) and 0.15 mg/kg the World Health Organization (WHO) limit. Moreover, the concentration of Cd was 3.0 mg/kg, which is above the permissible level of 0.2 mg/kg recommended by the EC and WHO. A positive correlation exists between the Cu, Pb, Fe and Cd concentration found in sediments and fish samples. The results show that the river Mtakuja is polluted by mining waste, domestic and agrochemical activities. This suggest that, there is a need for regular monitoring of heavy metal in river Mtakuja in order to monitor and protect aquatic organisms and health of benefactors of this river.

A simple and straightforward strategy for expedient access to benzoxazoles using chemically engineered 2D magnetic graphene oxide nanosheets as an eco-compatible catalyst.

Two-dimensional (2D) graphene oxide nanosheets serve as an excellent support material for immobilizing metal complexes to deal with the drawbacks of homogeneous catalysis. In this work, we report a magnetically retrievable graphene oxide (MGO) based copper nanocatalytic system that has been efficiently exploited for obtaining a series of pharmaceutically and biologically active benzoxazole scaffolds. The nanocatalyst was designed by covalent immobilization of dehydroacetic acid (DHA) onto a magnetic amino-silanized graphene oxide nanosupport which was accompanied by its metallation with copper acetate. The structure of the synthesized MGO hybrid material (Cu@DHA@APTES@MGO) was characterized by numerous physico-chemical techniques such as transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), elemental mapping, atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) surface area analysis and energy-dispersive X-ray fluorescence spectroscopy (ED-XRF). The fabricated architectures exhibited high efficiency for cyclization of 2-aminophenols and β-diketones with wide substrate scope, excellent functional group tolerance, a higher conversion percentage (>98%) and a high turnover number (TON). The exceptional catalytic activity could be attributed to the 2D architecture of graphene oxide which provides space for trapping of reactants between 2D graphitic overlayers and metal surfaces and the reaction proceeds to afford benzoxazole products with moderate to excellent conversion percentages. Notably, this nanocomposite could be recovered easily through an external magnetic force and reused for multiple runs without any appreciable loss in its catalytic efficacy.

Rapid screening of pharmaceutical products for elemental impurities by a high-resolution portable energy dispersive X-ray fluorescence spectrometer using an efficient fundamental parameter method.

In this study, a rapid screening method for elemental impurities in pharmaceutical products has been established by portable energy dispersive X-ray fluorescence (EDXRF) spectroscopy combined with the efficient fundamental parameter method. The proposed method has been used for the screening of 22 elemental impurities (i.e., Cd, Pb, As, Hg, Co, V, Ni, Tl, Au, Pd, Ir, Os, Rh, Ru, Se, Ag, Pt, Sb, Mo, Cu, Sn, and Cr) in the International Conference on Harmonization (ICH) Q3D guideline. The verification of results could meet the acceptance criteria for accuracy, precision and linearity in the United States Pharmacopoeia 〈233〉. On the other hand, the limit of quantitation of the proposed EDXRF method for the screening of 22 elemental impurities in pharmaceutical products could meet the concentration limits of each element at 10 g maximum daily intake based on the established permitted daily exposure to oral drugs in the ICH Q3D guideline. Our findings open up new possibilities in the rapid screening of pharmaceutical products for the detection of elemental impurities by EDXRF, which can be expected to provide a novel, nondestructive, high-throughput, portable, and sensitive platform for the process control of elemental impurities to ensure the quality and safety of drugs.

Ocorrência de laminite clínica após adaptação ao confinamento: efeitos na morfologia, densidade e composição mineral do casco de bovinos Nelore após terminação

ABSTRACT: Laminitis is a disease that affects the dermis and epidermis of the bovine hoof, generating changes in the hoof capsule. This study evaluated the effects of clinical laminitis diagnosed after the adaptation phase to confinement on the morphology, density, and mineral composition of the hoof of Nellore cattle after finishing. The animals were separated in the first weeks of confinement into a sick group (SG), with clinical laminitis, and a healthy group (HG). SG animals had higher heel length, dorsal wall length, toe height, and diagonal hoof length (p<0.05) than healthy animals. The dermal laminae had similar measurements for thickness, length, and spacing between them between SG and HG. Animals with laminitis showed congestion, hemorrhage, and basement membrane irregularities on histology. Computed microtomography (μCT) revealed that the hoof density of sick animals is lower than healthy ones. According to the mineral composition by energy-dispersive X-ray fluorescence (ED-XRF) spectrometry, the hooves of animals with laminitis (SG) and healthy ones (HG) were not biochemically different. Therefore, the occurrence of clinical laminitis in Nellore cattle in the first weeks of confinement causes an increase in the morphometric parameters of the hoof capsule and a reduction in the density of the abaxial hoof wall evaluated after the finishing period. This disease does not promote changes in the histomorphometric parameters of the dermal laminae and the percentage of minerals in the abaxial hoof wall.

Multi-Element Determination of Ferrochromium by Energy-Dispersive X-Ray Fluorescence Spectrometry Based on Design of Experiments

Multi-Element Determination of Ferrochromium by Energy-Dispersive X-Ray Fluorescence Spectrometry Based on Design of Experiments