Total Reflection X-ray Fluorescence Research Articles

Rapid Water Quality Analysis by Total Reflection X-ray Fluorescence Analysis

Rapid Water Quality Analysis by Total Reflection X-ray Fluorescence Analysis

Total-reflection X-ray fluorescence determination of thorium and uranium in the presence of interfering elements in solid geological objects of natural and technogenic origin

The insufficient spectral resolution of the energy-dispersive total-reflection X-ray fluorescence (TXRF) complicates the U and Th Lα lines using for the quantitative determination of low concentrations of these elements in natural solid samples.

Exploratory studies on total reflection X-ray fluorescence spectrometry combined with slurry sampling for the multi-element analysis of copper-nickel sulfide ore

Major and trace elements in polymetallic minerals are crucial subjects of study in ore geology.

Analysis of the Influence of Zn Excess in the Pineal Gland by Total Reflection X-ray Fluorescence

The TXRF technique (total reflection X-ray fluorescence) was employed to analyze the concentration of zinc (Zn) and other metals in the pineal gland of rats submitted to orally administered excess dose of Zn sulfate. The histochemical localization of Zn was also performed. TXRF results showed a 42.9% increase in Zn concentration, and alterations on the homeostasis of other essential elements in rats. It was concluded that TXRF is a suitable technique for measuring, for the first time in this work, the concentration of Zn accumulated in the pineal gland after administration of an excess dose of Zn, and this result may be either directly or indirectly related to alteration in the homeostasis of other chemical elements, such as S, Cl, K, Ca, Ti, Cr, Mn and Fe.

Active biomonitoring of potentially toxic elements in urban air by two distinct moss species and two analytical techniques: a pan-Southeastern European study

This is the first study to use moss transplants as a biomonitoring technique and inductively plasma mass spectrometry to investigate airborne potentially toxic element pollution and air quality in urban areas on a regional scale across nine Southeastern European countries. The mosses in bags were exposed for 2 months during the winter season (2019/2020) at five sites in each of the selected urban areas next to air quality (AQ) monitoring stations. The sites were selected concerning different land use classes (typical urban, residential, urban background, and rural sites). The concentrations of 35 elements were determined using inductively coupled plasma mass spectrometry. A comparison with elemental analysis performed by total reflection X-ray fluorescence is also presented. Concentrations of the potentially toxic element in moss bags exposed in urban areas were significantly higher, while those exposed in rural areas did not differ significantly from the initial content of unexposed moss. Linear regression analysis revealed no significant differences between the average concentrations of elements in H. cupressiforme and S. girgensohnii moss bags (linearity R2 = 0.94). It shows similar trends in elements in both moss species. The median values of contamination factors in both moss species ranged mostly from 1.2 to 2.17, indicating the exposure sites show no contamination to slight contamination status (C1 to C2 scales). High values of relative accumulation factors were found for Cr, Cu, Fe, Ni, Sb, and V in moss bags, indicating these elements are the most abundant in most sampling sites, which may increase human exposure through inhalation and could lead to harmful health problems.

Characterization of nebulization generated aerosol particles dispersion and deposition by total reflection X-ray fluorescence

Characterization of nebulization generated aerosol particles dispersion and deposition by total reflection X-ray fluorescence

Total reflection X-ray spectroscopy based detection of uranium and thorium in phosphogypsum simulated by Monte Carlo method

Detection of trace amounts of uranium and thorium in phosphogypsum using total reflection X-ray fluorescence (TXRF) was addressed by Monte Carlo method (MCNP code, version 6.2). The simulated samples contained average concentrations of 238U (120 Bq/kg) and 232Th (40 Bq/kg), as well as 7 major components in oxide forms and other 11 heavy metals in trace amounts, commonly found in PG. It was found that, for a molybdenum target X-ray tube operating under total reflection condition and equipped with an SDD detector, the detection limit for uranium and thorium in the simulated multi-elemental sample are (1.42±0.04)ng and (1.03±0.02)ng, respectively. Based on parameters of certified solutions for uranium and thorium, and adding gallium as an internal standard element, calibration plots provided mass recovery from the multi-component sample with relative errors of 4.56% for uranium and 2.74% for thorium. Our results show that TXRF technique can accurately detect and quantify trace amounts of uranium and thorium in the presence of matrix effects without any pre-treatment of PG samples.

Novel ferrocene-containing amphiphilic block copolymer nanoparticles as high-capacity charge carriers in aqueous redox flow systems

Size-exclusion polymer electrolytes are promising charge carriers to diminish the crossover and allowing commercially available low-cost porous membranes in redox flow batteries. Boosting the solubility in water and maximizing the number of redox sites to enhance the capacity of these polymeric systems is challenging. New highly water dispersed amphiphilic diblock copolymers are reported here, with an average concentration value of 1.7 10−3 mmol of Ferrocene (Fc)-linked moieties per mg of polymer, determined by total X-ray reflection fluorescence. These redox amphiphilic block copolymers are stabilized in water as spherical nanoparticles (20 nm) by using a simple phase solvent inversion procedure. We evidence a maximum polymer dispersibility value of 6 g/L in water, for long-term stable polymer nanoparticle suspensions, yielding a theoretical capacity value of 4.78 mAh at 10.5 mM Fc. Further adjustment of the ionic conductivity and pH of these stable redox block copolymer suspensions has rendered a conductivity value of 44.5 mS/cm at pH values close to a neutral one, by adding a variety of salt supports. Studies using a 3-electrode configuration cell reveal an efficient charge transport between each of the Fc motifs in the polymer nanoparticle. A capacity value of 3.1 mAh with no transient of the polymer nanoparticles crosswise the cheap porous membrane is evidenced when cycled as polycatholyte material in a Zn hybrid aqueous redox flow battery. The particle size and electronic changes of these novel amphiphilic redox block copolymer electrolytes during consecutive redox cycles have also been monitored by dynamic light scattering and ultraviolet-visible spectroscopy, respectively. The analysis of the results enables the understanding of the main mechanisms behind their non-fully reversible capacity. Among them, aggregation and sedimentation, along with retention inside the graphite felt electrode acting the latter as a filter. These insights will aid the design of future polymer electrolyte materials and redox flow battery components with better performance and cost.

Sorption of As(III) and Se(IV) from Aqueous Solutions for Subsequent Determination by Total Reflection X-Ray Fluorescence

Sorption of As(III) and Se(IV) from Aqueous Solutions for Subsequent Determination by Total Reflection X-Ray Fluorescence

A grazing incidence diffraction setup for Langmuir trough experiments at the high-resolution diffraction beamline P08 at PETRA III

The Langmuir Grazing Incidence Diffraction setup at the high-resolution diffraction beamline P08 of PETRA III is a dedicated setup for grazing incidence X-ray scattering measurements on Langmuir troughs. The instrument is optimized for low background grazing incidence X-ray diffraction measurements at vapour-water interfaces, while offering rapid layer structure assessment by grazing incidence X-ray off-specular scattering, and interfacial element analysis by total reflection X-ray fluorescence spectroscopy. Its control system is intuitive and standardized to provide easy access for non-expert users, and permits automated operation except for sample exchange.

Association of COVID-19 mortality with serum selenium, zinc and copper: Six observational studies across Europe.

Certain trace elements are essential for life and affect immune system function, and their intake varies by region and population. Alterations in serum Se, Zn and Cu have been associated with COVID-19 mortality risk. We tested the hypothesis that a disease-specific decline occurs and correlates with mortality risk in different countries in Europe. Serum samples from 551 COVID-19 patients (including 87 non-survivors) who had participated in observational studies in Europe (Belgium, France, Germany, Ireland, Italy, and Poland) were analyzed for trace elements by total reflection X-ray fluorescence. A subset (n=2069) of the European EPIC study served as reference. Analyses were performed blinded to clinical data in one analytical laboratory. Median levels of Se and Zn were lower than in EPIC, except for Zn in Italy. Non-survivors consistently had lower Se and Zn concentrations than survivors and displayed an elevated Cu/Zn ratio. Restricted cubic spline regression models revealed an inverse nonlinear association between Se or Zn and death, and a positive association between Cu/Zn ratio and death. With respect to patient age and sex, Se showed the highest predictive value for death (AUC=0.816), compared with Zn (0.782) or Cu (0.769). The data support the potential relevance of a decrease in serum Se and Zn for survival in COVID-19 across Europe. The observational study design cannot account for residual confounding and reverse causation, but supports the need for intervention trials in COVID-19 patients with severe Se and Zn deficiency to test the potential benefit of correcting their deficits for survival and convalescence.

A highly sensitive method for uranium quantification in water samples at ultra-trace level by total reflection X-ray fluorescence, after its direct pre-concentration on the surface of amidoxime functionalized quartz sample supports

In this work we have developed a Total reflection X-Ray Fluorescence (TXRF) based methodology for the determination of uranium in natural water samples at ultra-trace concentration level. The methodology involves functionalization of quartz sample supports used for TXRF measurements with (3-Amidoxy) triethoxysilane, which has very high uranium uptake efficiency. (3-Amidoxy) triethoxysilane has been synthesized from (3-Cyanopropyl) triethoxysilane (CPTS). This amidoxime functionalized sample supports, simply needed to be dipped in the uranium solution for 3 h after which, it can be directly taken for TXRF measurements. The developed methodology is very fast, simple with less sample preparation steps involved. The present work utilizes Rayleigh scattered peak to construct the calibration curve for the quantification purpose. The developed methodology has improved accuracy as well as precision for the quantification of uranium at such low concentrations level. The detection limit and accuracy obtained are 0.013 ng/mL (13 ppt) and 1.9%, respectively which are the lowest using any X-Ray Fluorescence based method, to the best of our knowledge. The method was successfully applied for the U determination in natural water samples like ground water, river water and sea water.

Green Extracellular Synthesis of Silver Nanoparticles by Pseudomonas alloputida, Their Growth and Biofilm-Formation Inhibitory Activities and Synergic Behavior with Three Classical Antibiotics.

Bacterial resistance to antibiotics is on the rise and hinders the fight against bacterial infections, which are expected to cause millions of deaths by 2050. New antibiotics are difficult to find, so alternatives are needed. One could be metal-based drugs, such as silver nanoparticles (AgNPs). In general, chemical methods for AgNPs' production are potentially toxic, and the physical ones expensive, while green approaches are not. In this paper, we present the green synthesis of AgNPs using two Pseudomonas alloputida B003 UAM culture broths, sampled from their exponential and stationary growth phases. AgNPs were physicochemically characterized by transmission electron microscopy (TEM), total reflection X-ray fluorescence (TXRF), infrared spectroscopy (FTIR), dynamic light scattering (DLS), and X-ray diffraction (XRD), showing differential characteristics depending on the synthesis method used. Antibacterial activity was tested in three assays, and we compared the growth and biofilm-formation inhibition of six test bacteria: Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We also monitored nanoparticles' synergic behavior through the growth inhibition of E. coli and S. aureus by three classical antibiotics: ampicillin, nalidixic acid, and streptomycin. The results indicate that very good AgNP activity was obtained with particularly low MICs for the three tested strains of P. aeruginosa. A good synergistic effect on streptomycin activity was observed for all the nanoparticles. For ampicillin, a synergic effect was detected only against S. aureus. ROS production was found to be related to the AgNPs' antibacterial activity.

The New Markers of Early Obesity-Related Organ and Metabolic Abnormalities.

The objective of our study was to identify new markers related to excessive body adiposity and its early consequences. For this purpose we determined serum FGF-19 and FGF-21 concentrations in obese rats, whose role in the pathogenesis of obesity is not yet established. In addition, a total reflection X-ray fluorescence technique was applied to determine the elemental chemistry of certain tissues affected by obesity. Next, the new biochemical and molecular parameters were correlated with well-known obesity-related markers of metabolic abnormalities. Our obese rats were characterized by increased calorie consumption and body adiposity, hypercholesterolemia, elevated levels of liver enzymes and FGF-21, while the level of FGF-19 was reduced. Strong relationships between new hormones and established metabolic parameters were observed. Furthermore, we demonstrated that obesity had the greatest effect on elemental composition in the adipose tissue and liver and that rubidium (Rb) had the highest importance in distinguishing the studied groups of animals. Tissue Rb strongly correlated with both well-known and new markers of obesity. In conclusion, we confirmed serum FGF-19 and FGF-21 as useful new markers of obesity-related metabolic alternations and we robustly propose Rb as a novel indicator of excessive body adiposity and its early consequences. However, further investigations are encouraged to address this clinical issue.

Improvement of suspension-assisted total reflection X-ray fluorescence analysis of ores using wet grinding and empirical calibrations

In this study, the suspension-assisted total-reflection X-ray fluorescence analysis of ores was improved using the wet grinding procedure to produce ultra-fine suspended powder mixed with internal standard solution in aqueous media. The advantages of the proposed technique were demonstrated by the example of the determination of S, Fe, Ni, and Cu in sulfide copper‑nickel ores containing various ratios of sulfide and silicate minerals. We showed that the powerful mixing of 100 mg of ore powder and 4 mL of ultra-pure water as a dispersing medium with 20 g of grinding balls of 1 mm in diameter leads to the preparation of homogeneous suspension with monomodal particle size distribution having 90% of the particle size <6 μm. The suspension after wet grinding was diluted up to 50 mL with ultra-pure water to obtain a final concentration of the suspended powder of 2 mg/mL. Relative precision of the described sample preparation technique calculated from duplicate pairs of suspensions was 16% for S, 9% for Fe, 15% for Ni and 10% for Cu. Three spectral data processing techniques were further compared with respect to the quantification accuracy of target elements: internal standard, univariate and multivariate regressions. It was shown that the two latter methods can be used to improve the trueness of the internal standard method, especially for Cu and Fe.

Comprehensive Analysis of Two H13-Type Starting Materials Used for Laser Cladding and Aerosol Particles Formed in This Process.

Laser cladding with H13 steel powders was performed and the related material transformations were studied for the particles emitted during this process. Fractions of various sizes of the aerosol particles formed during the laser cladding were collected on a cascade impactor, while the electromobility and the aerodynamic size of the particles were measured using a scanning mobility particle spectrometer and an aerodynamic particle sizer, respectively. The aerosol particles deposited onto the impactor plates were analyzed using scanning electron microscopy–energy-dispersive X-ray spectroscopy, as well as total-reflection X-ray fluorescence and X-ray absorption near-edge structure spectroscopy. Both the concentration and mean oxidation state of the major components were correlated with the aerosol particle size. The ultrafine aerosol particles (with a diameter less than about 100 nm) were predominantly oxidized and formed as the result of an evaporation–oxidation–condensation process sequence. The larger particles (>200 nm in geometric diameter) were primarily the residues of the original metal powder and exhibited a composition change as compared to the as-received metal powder. Correlations between the changes in the concentration ratio of the components were detected and explained.

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.

Toxic Elements in Sediment and Water of the Crocodile River (West) System, South Africa, Following Acid Mine Drainage

The upper reaches of the Crocodile River (West) system are located in the western basin of the Witwatersrand mountain chain, an area heavily influenced by gold mining. After the spill of highly acidic and contaminated mining-influenced water into the river system in 2002, chemical water treatment was implemented to compensate for the consequences of acid mine drainage. Some studies thereafter have shown metal concentrations of concern in the system, but never considered longer periods of time. For this study, we investigated water and sediments over a period of 13 months from 7 sampling sites in the system. In addition to physico-chemical parameters such as temperature, pH, and electrical conductivity, a multi-element analysis was conducted. We used various versions of atomic-absorption-spectroscopy, total reflection x-ray fluorescence spectroscopy, and inductively coupled plasma mass spectrometry in filtered and acidified water samples as well as sediment leachates. Concentrations of Ni, Zn, As, Pb, and U in the sediment were clearly elevated at the site closest to the mine as well as further downstream, some of them far exceeding quality guidelines. Moreover, dissolved Mn, Fe, Ni, Zn and U occurred irregularly in concentrations of concern at the site of mining-influenced water inflow. Our findings clearly indicate a risk of further and chronic mobilization of toxic elements from this site and a possible threat to the connected river system.

Analytical control of Mn and Se in synthesized compounds, promising plant-derived medicines, by WDXRF and TXRF methods

Some organic compounds extracted from plants serve as raw materials to synthesize new drugs. Quantification of the metal or semimetal bound with the organic molecule, and the control of foreign elements are very important to ensure the quality of the future medicinal products. In the synthesized compounds of Mn with dihydroquercetin (Mn-DHQ) and Se with arabinogalactan (Se-AG), it was required to determine the content of Mn and Se. The authors of the paper applied wavelength-dispersive (WDXRF) and total-reflection (TXRF) X-ray fluorescence methods to quantify above elements. In absence of suitable certified reference materials, the synthetic samples were prepared for calibration of WDXRF spectrometer. Two sample preparation procedures were used in the TXRF: acid digestion and dissolution by water. The Mn contents in compounds with DHQ amounted to 13.5–17.4% by WDXRF and 13.1–18.2% by TXRF. The Se contents in compounds with AG did to 0.5–12.9% and 0.5–13.6%, respectively. Statistical data processing did not reveal a significant difference between the results of two methods. To check the foreign elements in the synthesized substances the X-ray spectra were recorded. Some minor peaks in the energy range of 5.9–7.5 keV were found on TXRF spectrum of the Se-AG sample as the consequence of its contamination. The Mn complexes did not contain any foreign elements. Additionally, determined element contents were compared with ones calculated through chemical formulas of resulting compounds to characterize their cleaning level from impurities.

Synthesis of Trimetallic (Ni-Cu)@Ag Core@Shell Nanoparticles without Stabilizing Materials for Antibacterial Applications.

We report a simple method to prepare colloidal trimetallic (Ni-Cu)@Ag core@shell nanoparticles (NPs) without stabilizing materials. Experimental evidence was found for the successful synthesis of these NPs using X-ray diffraction (XRD), optical spectroscopy, and high-resolution transmission electron microscopy (HRTEM). The presence of core metals (Ni and Cu) was confirmed by elemental analysis using a total reflection X-ray fluorescence (TXRF) analysis. In addition, the absorption spectra of the prepared samples exhibited broad bands compared to the bands of the monometallic NPs, indicating the formation of a core–shell nanostructure. The antibacterial activity of the trimetallic NPs was evaluated against three Gram-negative (Pseudomonas aeruginosa, Escherichia coli, and Salmonella) and two Gram-positive (Streptococcus and Staphylococcus aureus) bacteria on Mueller–Hinton agar. These NPs showed high inhibition of bacterial growth at the low sample concentrations used in this study compared to other nanomaterials. One of the interesting results of the current study is that the inhibition zone of Pseudomonas aeruginosa as a resistant bacterium was high for most NPs. These results make the prepared samples promising candidates for antibiotic material applications.