Total Reflection X-ray Fluorescence Research Articles

Determination of S, Ni, Cu in copper-nickel sulfide ores by total reflection X-ray fluorescence analysis: experience of participation in the interlaboratory comparisons

The quality of the determination of S, Ni, Cu in copper-nickel sulfide ores was assessed in the framework of the program for interlaboratory comparative tests (ICT) using total reflection X-ray fluorescence analysis (TXRF) taking into account the criteria for methods for determining the chemical composition of mineral raw materials. Certified TXRF techniques for the analysis of mineral materials are absent, so the interlaboratory comparison test was used to control and improve the accuracy of measurements by TXRF. Powdered ore samples were prepared as suspensions by wet grinding: 100 mg of the powder, 4 ml of ultra-pure water and 250 μl of the Ga standard solution were milled using 20 g of ZrO2 balls 1 mm in diameter in the mixing mill for 10 minutes at a frequency of 20 Hz. The ratio of the intensities of the characteristic lines of the analyzed elements and the Ga internal standard was chosen as an analytical signal. To plot calibration curves, a set of ore reference samples was analyzed using certified procedures (atomic absorption spectrometry for Cu, Ni, gravimetry for S). The quality of the TXRF analysis was assessed by the value of Z-criterion. The measurement error did not exceed 5 rel. %. The relative percentage differences between the TXRF results and the results obtained in the interlaboratory study was less than 10%. The described method can be used for rapid analysis of copper-nickel sulfide ores.

Determination of macro‐ and microelements concentrations by wavelength‐dispersive X‐ray fluorescence spectrometry in the objects of the technogenic ecosystem

AbstractThe wavelength‐dispersive X‐ray fluorescence (WDXRF) spectrometry was applied to determine Na, Mg, Al, P, S, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, and Pb concentrations in the needles of dwarfish spruce Picea canadensis conica and the blue prickly spruce Picea pungens glauca, as well in technogenic soil of Irkutsk city, in which these spruce species grow. All measurements were performed in vacuum using WDXRF spectrometer S8 TIGER produced by Bruker AXS, Germany. The calculated values of instrumental limit of detection (ILD) ranged from 0.5 for Ni to 67 mg/kg for Al for soil certified reference materials (CRMs) such as OOKO151 (light chestnut soil) and from 0.2 for Cu and Ni to 18–24 mg/kg for Na for the plant CRMs such as LB‐1 (birch leaf) and EC‐1 (Canadian waterweed). The repeatability is satisfactory. The values of relative standard deviations (RSDs) do not exceed 15% for soils and available plant material. With calculated T‐statistics, it was found that the WDXRF data do not contain systematic errors. The values of relative discrepancy for WDXRF, total reflection X‐ray fluorescence (TXRF) spectrometry, and atomic emission spectrometry with arc discharge (d.c. arc‐AES) results do not exceed 30% for studied elements.

Ecological and human health risk assessment of heavy metal contamination in soils of major industrial estates of Tamil Nadu, India

ABSTRACT This study endeavoured to determine the current status of heavy metal contamination in soils around leather industrial areas of Tamil Nadu and the associated environmental and human health risks. Accordingly, 31 soil samples were examined using the total reflection X-ray fluorescence (TXRF) spectroscopy technique. From TXRF results, the mean concentrations of heavy metals (mg kg−1, dry weight) were obtained in the trend of Fe (9234.03) > Al (592.00) > Cr (194.99) > Sr (148.76) > Mn (137.61) > Cl (81.79) > Zn (38.97) > Cu (38.33) > V (36.78) > Pb (31.18) > Ni (9.81) > As (1.12). The pollution indices such as geo-accumulation index (Igeo), contamination factor (CF), and enrichment factor (EF) revealed the significant contaminants in the study area. The hazard index (HI) indicated that non-carcinogenic risk (NCR) due to heavy metals were negligible for both adults and children (HI < 1). In addition, total cancer risk (TCR) showed carcinogenic risk (CR) for adults (TCR = 1.38 × 10−4) and children (TCR = 1.27 × 10−3) are moderate and higher, respectively. Multivariate statistical analyses such as Pearson correlation analysis (CA), hierarchical cluster analysis (HCA), and factor analysis (FA) revealed that the heavy metals derived from various sources such as lithogenic and anthropogenic. Overall, special concern is advised to the inhabitants, especially with regard to children, in the study area about the health risks due to the anthropogenic inputs.

Screening Cobalt-based Catalysts on Multicomponent CdSe@CdS Nanorods for Photocatalytic Hydrogen Evolution in Aqueous Media.

We present CdSe@CdS nanorods coated with a redox-active polydopamine (PDA) layer functionalized with cobaloxime-derived photocatalysts for efficient solar-driven hydrogen evolution in aqueous environments. The PDA-coating provides reactive groups for the functionalization of the nanorods with different molecular catalysts, facilitates charge separation and transfer of electrons from the excited photosensitizer to the catalyst, and reduces photo-oxidation of the photosensitizer. X-ray photoelectron spectroscopy (XPS) confirms the successful functionalization of the nanorods with cobalt-based catalysts, whereas the catalyst loading per nanorod is quantified by total reflection X-ray fluorescence spectrometry (TXRF). A systematic comparison of different types of cobalt-based catalysts was carried out, and their respective performance was analyzed in terms of the number of nanorods and the amount of catalyst in each sample [turnover number, (TON)]. This study shows that the performance of these multicomponent photocatalysts depends strongly on the catalyst loading and less on the specific structure of the molecular catalyst. Lower catalyst loading is advantageous for increasing the TON because the catalysts compete for a limited number of charge carriers at the nanoparticle surface. Therefore, increasing the catalyst loading relative to the absolute amount of hydrogen produced does not lead to a steady increase in the photocatalytic activity. In our work, we provide insights into how the performance of a multicomponent photocatalytic system is determined by the intricate interplay of its components. We identify the stable attachment of the catalyst and the ratio between the catalyst and photosensitizer as critical parameters that must be fine-tuned for optimal performance.

Insights into the Age-Dependent Variation in Nutrition-Related Trace Elements in Diabetes Blood Using Total Reflection X-Ray Fluorescence.

The prevalence of diabetes has reached alarming levels in India, making it essential to understand the concentration of nutritional-trace elements (Fe, Cu, Zn, Cr. and Se) in blood samples from diabetic adults. In this study, 208 whole blood samples from diabetic (n = 104) and non-diabetic (n = 104) adults across various age groups were analyzed using total reflection X-ray fluorescence (TXRF) spectroscopy with a sample dilution method. Statistical analysis was performed to assess descriptive statistics and determine a significant correlation between elemental concentrations in the blood samples of diabetic and non-diabetic adults. The mean concentration of nutritional-related trace elements in diabetic blood was as follows: Fe (46 ± 5) > Zn (1.28 ± 0.14) > Cu (0.10 ± 0.01) > Cr (0.05 ± 0.004) > Se (0.013 ± 0.001) in mg/L, respectively. Additionally, this study investigated the influence of nutrition-related trace element concentrations across various age groups such as 25-40years (young adults), 41-55years (middle-aged adults), and 56-70years (older adults). In this investigation, Zn (p < 0.001) and Cr (p < 0.05) concentrations differed significantly between diabetic and non-diabetic adults aged 56-70years. These findings will help us to understand age-dependent changes in element concentrations, clarify their role in diabetes, and improve risk factor management associated with diabetes.

Inflammation subsequent to mild iron excess differentially alters regional brain iron metabolism, oxidation and neuroinflammation status in mice.

Iron dyshomeostasis and neuroinflammation, characteristic features of the aged brain, and exacerbated in neurodegenerative disease, may induce oxidative stress-mediated neurodegeneration. In this study, the effects of potential priming with mild systemic iron injections on subsequent lipopolysaccharide (LPS)-induced inflammation in adult C57Bl/6J mice were examined. After cognitive testing, regional brain tissues were dissected for iron (metal) measurements by total reflection X-ray fluorescence and synchrotron radiation X-Ray fluorescence-based elemental mapping; and iron regulatory, ferroptosis-related, and glia-specific protein analysis, and lipid peroxidation by western blotting. Microglial morphology and astrogliosis were assessed by immunohistochemistry. Iron only treatment enhanced cognitive performance on the novel object location task compared with iron priming and subsequent LPS-induced inflammation. LPS-induced inflammation, with or without iron treatment, attenuated hippocampal heme oxygenase-1 and augmented 4-hydroxynonenal levels. Conversely, in the cortex, elevated ferritin light chain and xCT (light chain of System Xc-) were observed in response to LPS-induced inflammation, without and with iron-priming. Increased microglial branch/process lengths and astrocyte immunoreactivity were also increased by combined iron and LPS in both the hippocampus and cortex. Here, we demonstrate iron priming and subsequent LPS-induced inflammation led to iron dyshomeostasis, compromised antioxidant function, increased lipid peroxidation and altered neuroinflammatory state in a brain region-dependent manner.

Synthesis and Characterization of (CdO- CuOCo3O4) Mixed Metal Oxides Nanocomposite

The main goals of this study are to synthesize a mixed metal oxide nanocomposite (NC), CdO-CuO-Co3O4, and to analyze its structural, morphological, optical, and electrical properties using X-ray diffraction (XRD), total reflection X-ray fluorescence (TXRF), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), and DC electrical resistivity. According to the XRD analysis, CuO nanoparticles (NPs) have a monoclinic structure, while CdO and Co3O4 (NPs) have cubic structures. The TEM images revealed a decrease in the particle size of CdO-CuO-Co3O4 (NC) compared with that of the NPs. The optical properties of CdO-CuO- Co3O4 (NC) were examined using a DRS in the wavelength range of 400-700 nm. The DC electrical resistivity results showed the semiconducting electrical behaviors of the samples.

Development of a cascade impactor optimized for size-fractionated analysis of aerosol metal content by total reflection X-ray fluorescence spectroscopy (TXRF)

Development of a cascade impactor optimized for size-fractionated analysis of aerosol metal content by total reflection X-ray fluorescence spectroscopy (TXRF)

Effects of surface property on loading octaaza bis-α-diimine Ni complex, charge separation, and H2 production activity of MnS@ZnS photocatalysts

The MnS@ZnS photocatalyst was prepared using a microwave-assisted solvothermal method. Then, the octaaza bis-α-diimine Ni complex was loaded to prepare a composite photocatalyst. The adsorption of metal complex on photocatalyst depends on the anchoring groups of the Ni complex and the colloidal surface charge of the photocatalyst. The effects of the zeta potential of MnS and MnS@ZnS photocatalysts on the loading of Ni complex, separation of photogenerated carriers, and activity of Ni complex-modified composite photocatalysts were studied. The loading of NiC complex in photocatalysts was analyzed by Raman spectra, TEM line scan, mapping images, and total reflection x-ray fluorescence spectrometer. MnS@ZnS photocatalyst exhibits negative zeta potential that provides a strong electrostatic attraction force between photocatalysts and the Ni complex (Columb attraction), leading to increased Ni complex loading. MnS@ZnS/Ni complex exhibits better photocatalytic activity than MnS/Ni complex. Loading the Ni complex facilitates the photosensitization of photocatalysts, resulting in improved light absorbance. Besides, the electron-hole separation was further improved because the Ni complex acted as a redox mediator, enabling the transfer of electrons from MnS@ZnS to the Ni complex. The H2 production activity of MnS@ZnS/Ni complex photocatalyst reaches 3997 μmol h−1g−1, which is 1.72 times the pristine MnS.

Quantifying salivary iodine biomarker using total reflection X-ray fluorescence (TXRF): A method for assessing and monitoring iodine status simulated by Monte Carlo

Iodine stands as a vital trace element essential crucial for synthesizing thyroid hormones, which are essential for regulating metabolism and tissue growth. The “gold standard” for assessing iodine status in a population quantifies the iodine content in urine samples and is based on Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). Such method, or methods involving the readings of the Sandell-Kolthoff (SK) reaction, require complex sample preparations and the use of several toxic chemical elements. However, recent studies have shown a strong correlation between urinary iodine content (UIC) and iodine present in saliva. Using Monte Carlo simulations, this paper presents a TXRF-based method to quantify salivary iodine biomarker for assessing and monitoring iodine status. In the theoretical analysis, mono and polychromatic (filtered) excitation sources are considered. The detection and quantification limits of iodine, as well as the calibration curves for mass recovery, used the strong I Kα1 and I Kα2 lines. It was found that the optimal X-ray excitation source energy for iodine detection is 50 keV monochromatic X-rays. In contrast, using simulated spectra from a tungsten anode target, the best result was found at 70 kVp (peak voltage), after filtering the white beam with a copper absorber. Detection limits of iodine are 0.121 ng and 2.292 ng, for mono and polychromatic sources, respectively. The theoretical results of this paper show that TXRF could be a fast, simple and accurate alternative to ICP-MS or SK reaction-based methods. Of clinical significance, quantifying salivary iodine using TXRF to assess and monitor iodine status could be particularly helpful to patients undertaking 131I treatment. In addition, it could be used in epidemiological field studies to determine iodine deficiency/excess in children and pregnant women.

Quantification of [99Tc]TcO4- in urine by means of anion-exchange chromatography–aerosol desolvation nebulization–inductively coupled plasma–mass spectrometry

To sensitively determine 99Tc, a new method for internal quantification of its most common and stable species, [99Tc]TcO4-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{O}}_{4}^{-}$$\\end{document}, was developed. Anion-exchange chromatography (IC) was coupled to inductively coupled plasma–mass spectrometry (ICP-MS) and equipped with an aerosol desolvation system to provide enhanced detection power. Due to a lack of commercial Tc standards, an isotope dilution-like approach using a Ru spike and called isobaric dilution analysis (IBDA) was used for internal quantification of 99Tc. This approach required knowledge of the sensitivities of 99Ru and 99Tc in ICP-MS. The latter was determined using an in-house prepared standard manufactured from decayed medical 99mTc-generator eluates. This standard was cleaned and preconcentrated using extraction chromatography with TEVA resin and quantified via total reflection X-ray fluorescence (TXRF) analysis. IC coupled to ICP-MS enabled to separate, detect and quantify [99Tc]TcO4-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{O}}_{4}^{-}$$\\end{document} as most stable Tc species in complex environments, which was demonstrated in a proof of concept. We quantified this species in untreated and undiluted raw urine collected from a patient, who previously underwent scintigraphy with a 99mTc-tracer, and determined a concentration of 19.6 ± 0.5 ng L−1. The developed method has a high utility to characterize a range of Tc-based radiopharmaceuticals, to determine concentrations, purity, and degradation products in complex samples without the need to assess activity parameters of 99(m)Tc.Graphical

Statistical analysis of analytical results near detection limits with illustrations using elemental determinations in medical and biological samples by total reflection X-ray fluorescence

The following paper presents statistical analysis of measurement results close to the detection limit of an analytical technique and being random-left censored data. For such observations the measured value is not known precisely but is restricted by the detection limit. In the paper, the idea of random-left censored observations and data analysis are presented generally and next it is shown how to include censored observations into the statistical analysis with the use of available statistical analysis software (survival analysis procedure). Statistical procedure is presented on the examples of the X-ray spectroscopic analysis of element concentrations in medical and biological samples. Censored observations are included in data analysis and quartiles are estimated. Additionally, two- and multigroup comparison is presented for the censored observations. The accuracy of the presented procedure is demonstrated and discussed on the basis of Monte-Carlo simulations.

Glioblastoma multiforme influence on the elemental homeostasis of the distant organs: the results of inter-comparison study carried out with TXRF method

Glioblastoma (GBM) is a fast-growing and aggressive brain tumor which invades the nearby brain tissue but generally does not spread to the distant organs. Nonetheless, if untreated, GBM can result in patient death in time even less than few months from the diagnosis. The influence of the tumor progress on organs other than brain is obvious but still not well described. Therefore, we examined the elemental abnormalities appearing in selected body organs (kidney, heart, spleen, lung) in two rat models of GBM. The animals used for the study were subjected to the implantation of human GBM cell lines (U87MG and T98G) characterized by different levels of invasiveness. The elemental analysis of digested organ samples was carried out using the total reflection X-ray fluorescence (TXRF) method, independently, in three European laboratories utilizing various commercially available TXRF spectrometers. The comparison of the data obtained for animals subjected to T98G and U87MG cells implantation showed a number of elemental anomalies in the examined organs. What is more, the abnormalities were found for rats even if neoplastic tumor did not develop in their brains. The most of alterations for both experimental groups were noted in the spleen and lungs, with the direction of the found element changes in these organs being the opposite. The observed disorders of element homeostasis may result from many processes occurring in the animal body as a result of implantation of cancer cells or the development of GBM, including inflammation, anemia of chronic disease or changes in iron metabolism. Tumor induced changes in organ elemental composition detected in cooperating laboratories were usually in a good agreement. In case of elements with higher atomic numbers (Fe, Cu, Zn and Se), 88% of the results were classified as fully compliant. Some discrepancies between the laboratories were found for lighter elements (P, S, K and Ca). However, also in this case, the obtained results fulfilled the requirements of full (the results from three laboratories were in agreement) or partial agreement (the results from two laboratories were in agreement).

Evaluations of the optimal plasma treated area in total reflection X-ray fluorescence analysis and the retention period of superhydrophilic ability of the substrate

An atmospheric pressure plasma jet was applied to control the form of a dried residue for total reflection X-ray fluorescence analysis.

An overview of the applications of total reflection X-ray fluorescence spectrometry in food, cosmetics, and pharmaceutical research

Ensuring reliable elemental analysis in food, cosmetic and pharmaceutical research is a prerequisite to human safety. Here we report on the use of total reflection X-ray fluorescence spectrometry, its state-of the art and challenges in those fields.

Monitoring of toxic metals and metalloids in the urine of non‐professional sportsmen using total reflection x‐ray fluorescence

AbstractExposure to toxic metals and metalloids is a significant public health concern and can seriously affect human health. The aim of this study was to establish the presence of toxic metals and metalloids in the urine of non‐professional sportsmen who participated in a mountain ultramarathon using a benchtop total reflection x‐ray fluorescence (TXRF) system. TXRF allows for easy and rapid sample preparation and is therefore a potential candidate for simple and cost‐effective analysis. In this work, the TXRF‐Mo system was used for multielement analysis of the urine samples of 21 non‐professional athletes who ran a 53 km mountain ultra‐marathon. Urine samples were collected at four time points, at the beginning of the race (pre‐race samples), immediately, and 12 and 24 h post‐race. Al, As, Ba, Ni, Pb, Rb, Sr, V, and Tl were detected in the collected urine samples. The accuracy and precision of the proposed methods were verified by the analysis of reference materials (Seronorm™ Trace Elements Urine Level 2). The TXRF results were in agreement with the reference values and no significant differences were observed at the 95% confidence level. The detection limits for the elements of interest were also reasonable considering their concentration ranges in real samples. Changes were observed over time with increasing average urinary metals and metalloids levels, but only two significant results, were an increase in As and Rb. The results indicate a high degree of inter‐subject variability. The results obtained show that the content of toxic metals and metalloids increases in the urine samples collected after the race, which could confirm the statement that physical activity can increase the excretion of toxic metals and metalloids from the body. The simplicity of the TXRF method as well as its fast performance make it suitable for routine analysis.

Can amine ligands atomically disperse Cu atoms on TiO2(110)? Cu deposition on TiO2(110) premodified with o-anthranilic acid

Abstract The three-dimensional (3D) structure of evaporated Cu atoms on a TiO2(110) surface premodified with o-anthranilic acid (o-AA) was examined using polarization-dependent total reflection fluorescence X-ray absorption fine structure (PTRF-XAFS) to elucidate the effect of the premodification on the Cu dispersion over the TiO2(110) surface. Cu was found to be atomically dispersed with the formation of N–Cu–O bonds (where the N is provided by the o-AA and the O is present in the TiO2 lattice) on the surface, and the factors for controlling the atomic dispersion are discussed.

Ultrasensitive determination of selenium in food samples and its speciation in water and beverages using thiosemicarbazide-incorporated graphene and total-reflection X-ray fluorescence spectrometry

The paper presents a new analytical procedure for the determination and speciation of trace and ultratrace selenium in water, beverages, seafood, milk, and vegetables. The developed method is based on the dispersive micro-solid phase extraction with the use of new thiosemicarbazide-incorporated graphene as a solid sorbent, in combination of the total-reflection X-ray fluorescence spectrometry (TXRF). As a result, we have created an auspicious analytical tool for fast and sensitive analysis of samples with a complex matrix. Regardless of the specimen type, the method is characterized by a very low detection limit of 1.7 pg mL−1 and high precision. The developed strategy allowed us to solve common problems associated with selenium loss during the sample preparation for the TXRF measurement and also improve its performance toward the analysis of beverages and high saline/solid samples, which may even be impossible to perform using standard sample preparation procedures for a TXRF measurement.

Phenotypic Diversity and Genetic Parameters of Coffea canephora Clones

The simultaneous analysis of the maximum number of chemical elements present in plant tissues provides more comprehensive information about their chemical constitution and increases the number of characteristics for the selection process in various plant breeding programs. The objective of this study was to analyze productivity, grain yield, and concentration of chemical elements in tissues of Coffea canephora clones to study phenotypic diversity and estimate genetic parameters for use in breeding. This experiment was carried out in Manaus, Amazonas, Brazil, in randomized blocks with four replications. The concentrations of elements in various organs were quantified using total reflection X-ray fluorescence (TXRF). Genetic parameters and genetic divergence were estimated, and genotypes were clustered using the UPGMA hierarchical method and non-metric multidimensional scaling analysis. The study allowed us to differentiate the performance of the clones in terms of the absorption of essential and non-essential chemical elements for plant development and to analyze the correlation of the characteristics in the selection process. TXRF efficiently characterizes the presence and concentration of multiple elements, aiding genotype discrimination for C. canephora improvement.

Effect of sample carriers on analytical parameters in total reflection X-ray fluorescence - a tool for multi-trace elemental analysis

The Total reflection X-ray Fluorescence technique is increasingly popular for its simplicity and rapid elemental screening. This study evaluates the various analytical parameters including spectroscopic resolution, absolute sensitivity, relative element sensitivity, lowest limits of detection, accuracy and precision of the Total reflection X-ray Fluorescence spectrometer. This evaluation is conducted using quartz and acrylic sample carriers with mono and multi-element standards. Notably, the quartz sample carrier demonstrated excellent values of spectroscopic resolution, absolute sensitivity, the lowest limits of detection, a recovery rate of 90–110% and a coefficient of variation of 3–6% for the quantified elements from mono and multi-element standards. These findings underscore the robust analytical capability of the Total reflection X-ray Fluorescence technique for multi-trace elemental analysis. This research article not only provides practical and straightforward guidelines for handling Total reflection X-ray Fluorescence spectrometer but also confirms the practicality and effectiveness of the sample carriers for rapid and reliable elemental screening applications.