Application Of X-ray Fluorescence Spectrometry Research Articles

Applicability of X-ray fluorescence spectrometry for assessing geochemical features and heavy metal contamination of soils: primary data

ABSTRACT X-ray fluorescence spectrometry (XRF) has long been considered a convenient and powerful method for the determination of trace amounts of chemical elements in various types of natural materials. XRF is rapid, reliable, and non-destructive spectroscopic technique, allows performing a direct analysis of solid samples without pretreatment. For the present report, we take advantage of the multielemental capability of the XRF-technique for the determination of major and trace amounts of rock-forming (Stot, Na2O, MgO, Al2O3, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3(tot)) and trace (F, V, Cr, Co, Ni, Cu, Zn, Ga, Pb, Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Nd) elements in environmental solid samples. Nowadays, study of the soil cover exposed by human-caused impact is an important aspect in understanding the geochemical processes occurring in it. Study object is the biggest territory of the Baikal region named Olkhon, which is a natural area of preferential protection of federal significance and a part of the Baikal National Park. In this study, we have determined chemical composition of the soil upper horizon (~0–15 cm) of meadow-stepper landscapes of the Baikal region (the Olkhon Island) to reveal their geochemical features and heavy metal pollution level. Three varieties of the steppe soils were distinguished: middle loamy, light loamy and sandy loam. For the first time, the influence of soil granulometric features on the content level of the rock-forming and toxic elements in them has been established. In addition, the primary data relating to the assessment of the soil heavy metal contamination have been presented.

Application of x-ray fluorescence spectrometry in assesment of ultrafiltration membrane surface condition at water pre- treatment units of thermal power plants

The objects of the study were the Doy Chemical hollow-fiber ultrafiltration membranes which were use for preparation of make-up water for the Novocherkasskaya Regional Thermal Power Plant (RTPP).We tried out a possibility of applying the X-ray fluorescence spectrometry to study the condition of the spent non-recoverable ultrafiltration membranes in order to identify the causes of their irreversible destruction. The ARL Quant’X X-ray fluorescence energy dispersive spectrometer of Thermo Scientific (USA) was used in the study.Thin cuts of the Doy Chemical hollow-fiber ultrafiltration membranes were used in the experiments, which had worked for more than three years in the field conditions of the feed water of the Don River, Russia.The analysis of the obtained samples spectra allowed us to assume that the membranes were irreversibly contaminated by iron bacteria. Basing on the conclusions made during the analysis of X-ray fluorescence spectra we developed and tested in field conditions one of the optimization variants for technological pretreatment scheme. This scheme enables a significant increase in the service life of ultrafiltration membranes, even when the feed water is heavily contaminated by bacteria. Field tests of the modernized technology were carried out at Novocherkasskaya RTPP during 2016-2018 and showed a significant increase in the service life of the membrane modules. At the same time, the quality of the filtrate, productivity and pressure drops at the cascades of ultrafiltration units fully corresponded to the normative values even in conditions of deteriorated quality of the feed river water.It has been proved that aggressive regeneration of ultrafiltration membranes that have worked for a long time under the conditions of feed water having increased values of the total microbial number and high values of permanganate oxidation does not allow one to restore their initial state. In this case the main cause of ultrafiltration membranes contamination is iron, which is present in colloidal and bacterial forms in the pores and on the membranes surfaces. In the conditions of the Novocherkasskaya RTPP, in addition to timely flushing and chemical regeneration of ultrafiltration membranes, the necessity of organizing a preliminary treatment of the feed water with reagents having a prolonged bactericidal effect is accepted.

Application of X-ray fluorescence spectrometry for screening pharmaceutical products for Elemental Impurities according to ICH guideline Q3D

Energy-dispersive X-ray fluorescence spectrometry (EDXRF) is a suitable analytical procedure for screening drug products for Elemental Impurities (EI) according to ICH guideline Q3D. EDXRF represents a cost-efficient, robust and standard-free alternative compared to other methodologies for trace analysis, and therefore utilization of this application should be encouraged. This study demonstrates the capability of EDXRF for EI screening of oral solid dosage drug products (OSD products) within a defined matrix range. Method development and validation focused on class 1 (Cd, Pb, As, Hg) and class 2A (Co, V, Ni) elements, as defined by ICH guideline Q3D. In order to limit validation activities, a novel cluster approach was applied, based on matrix properties. This included comprehensive characterization of method performance parameters for exemplary pharmaceutical matrices and demonstration of LOQ independence from matrix effects by using a set of limit samples representing typical matrix variations of OSD products. The methodology can be used as a limit test for class 1 and class 2A elements and is fully compliant with method validation requirements according to the European Pharmacopeia. The novelty of the present work is the application of EDXRF for a routine screening of OSD products for Elemental Impurities within the pharmaceutical industry beyond previously published feasibility studies for a limited number of pharmaceutical raw materials or products.

Potential and application of X-ray fluorescence spectrometry to estimate iron and zinc concentration in potato tubers

Breeding efforts to develop high iron and zinc potatoes require a fast and inexpensive technique to evaluate mineral concentrations in large numbers of samples. In this study, we evaluated the feasibility of applying X-ray fluorescence spectrometry to estimate iron and zinc in freeze-dried and milled potato tuber samples. The calibration, and the external and independent validations showed high coefficients of determination, 0.93–0.96 for iron and 0.92–0.97 for zinc, and low standard errors, 1.10–1.44 mg/kg DW for iron and 0.91–1.06 mg/kg DW for zinc concentrations, indicating that iron and zinc can be estimated by X-ray fluorescence spectrometry with high precision. The developed calibrations were applied to estimate iron and zinc concentrations of hundreds of biofortified potato clones from the International Potato Center’s breeding program, grown in 3 distinct locations of Peru. Twenty clones showing high iron concentration (above 32 mg/kg DW) and 13 clones with high concentration of zinc (above 25 mg/kg DW) were identified. X-ray fluorescence spectrometry provides a rapid, low cost and suitable tool for potato breeders, compared to inductively coupled plasma optical emission spectrometry for screening iron and zinc concentrations, especially when a high number of potato clones must be evaluated in a short time frame.

Application of X-ray fluorescence spectrometry to determination and quantitation of metals in vegetal material

Determination of the chemical composition of vegetal matrices in the environmental and industrial fields has been increasing in the past few years. For analysis of vegetal specimens, X-ray fluorescence (XRF) spectrometry provides the desired features, including multi-element capability, simple sample preparation, wide dynamic range, high throughput and low cost per determination. This article gives an overview of the state of the art of XRF spectrometry for elemental determination and quantitation in vegetal samples. We give a brief description of sample-preparation procedures and then discuss physical and chemical effects of matrices involved when dealing with vegetal materials. We give special attention to current instrumentation, and we highlight advantages and limitations of each configuration. We comment on trends and the future outlook for XRF spectrometry in this application.

Fast application of X-ray fluorescence spectrometry aboard ship: how good is the new portable Spectro Xepos analyser?

A technique for onsite application of X-ray fluorescence (XRF) spectrometry to samples from sediment cores aboard a research vessel was developed and tested. The method is sufficiently simple, precise, and fast to be used routinely for high-resolution analyses of depth profiles as well as surface samples. Analyses were performed with the compact high-performance energy-dispersive polarisation X-ray fluorescence (EDPXRF) analyser Spectro Xepos. Contents of the elements Si, Ti, Al, Fe, Mn, Mg, Ca, K, Sr, Ba, Rb, Cu, Ni, Zn, P, S, Cl and Br were simultaneously determined on 200–225 samples of each core within 24 h of recovery. This study presents a description of the employed shipboard preparation and analysis technique, along with some example data. We show land-based datasets that support our decisions to use powder samples and to reduce the original measuring time for onboard analyses. We demonstrate how well the results from shipboard measurements for the various elements compare with the land-based findings. The onboard geochemical data enabled us to establish an element stratigraphy already during the cruise. Correlation of iron, calcium and silicon enrichment trends with an older reference core provided an age model for the newly retrieved cores. The Spectro Xepos instrument performed without any analytical and technical difficulties which could have been caused by rougher weather conditions or continuous movement and vibration of the research vessel. By now, this XRF technique has been applied during three RV Meteor cruises to approximately 5,000 Late Quaternary sediment samples from altogether 23 gravity cores, 25 multicorer cores and two box cores from the eastern South Atlantic off South Africa/Namibia and the eastern Atlantic off NW Africa.

Identification of paint and leather by X-ray fluorescence spectrometry with pyroelectric crystal

Applications of X-ray fluorescence spectrometry with a pyroelectric X-ray generator were studied. The X-ray generator with a pyroelectric crystal has unique features, such as small dimensions, low power, battery drive and a production of a periodically changing X-ray flux. Paint and leather samples were analyzed with this novel X-ray generator, and the performance of this device as an X-ray source for X-ray fluorescence spectrometry was investigated.

Application of X-ray fluorescence spectrometry in multielement analysis of rubber samples

Elemental analysis of rubber samples is rather difficult, but XRF spectrometry offers some advantages relative to other more popular chemical instrumental techniques due to relatively simple sample preparation. For the excitation annular radionuclide photon sources of 55Fe and 109Cd were used. The analyses of metal content in samples of natural latex have been performed in order to investigate the relation between the low specific resistivity of the latex and the respective metal content. The results are presented and discussed.

Möglichkeiten der Röntgenfluoreszenz- und Röntgenemissions-Spektrometrie in der Werkstoffanalytik

The principles and applications of X-ray fluorescence spectrometry and X-ray emission in the electron microprobe analysis and low energy electron induced X-ray spectrometry were described. With the help of soft X-ray spectra, arising from the valence bands, the different aluminum and titanium compounds of precipitates in steel can be investigated. The precipitates were isolated by an galvanostatic electrolysis. For speciation of aluminum the Kβlines in the X-ray fluorescence spectrum were investigated. The composition of aluminum oxide and -nitride in precipitates of special steel qualities can be determined. In the case of the speciation of titanium a direct electron bombardment of the sample is used to generate soft-X-rays. By investigating the L-lines of titanium different species like titaniumcarbide,-nitride or sulphide can be distinguished.

An Application of X-ray Fluorescence Spectrometry to the Study of Thin-Layer Chromatography

The combination of thin-layer chromatography (TLC) with X-ray fluorescence spectrometry (XRF) has been accomplished without any interfaces. It enables the direct, nondestructive visualization of elements developed on a TLC plate. In addition to inorganic compounds, organic compounds including electronegative elements can be detected simultaneously that cannot always be measured satisfactorily by competitive techniques; e.g., phenolic compounds containing chlorine, bromine, or iodine were distinctly detected by individual elemental imaging. The background of commercially available TLC plates with various thicknesses of the stationary phase and an outline of element detection limits were also investigated. TLC/XRF was found suitable for in situ TLC imaging of elements.

Application of X-ray fluorescence spectrometry in assessment of environmental pollution

A conventional X-ray fluorescence (XRF) method as well as total reflection XRF have been applied to the analysis of various environmental materials. Some methodological changes in order to extend the applicability range and improve the accuracy of the XRF analysis are also discussed.

Areas for Improvement in XRF Analysis of Low Atomic Number Elements

Accurate analysis of the light elements has been, from the early applications of X-ray fluorescence spectrometry a struggle compared to the determination of heavy elements in the same matrices. In contrast, there has been virtually no upper limit to the atomic number of the element that could be determined. The lower limit, however, has been continuously adjusted downward through the years. Clearly, the sensitivity as well as the lower limit of detection for the heavy elements have also been improved, but the effect is Jess striking than the advances made in the region of tight element performance. This paper deals specifically with wavelength dispersive sequential x-ray fluorescence spectrometry, although some of the observations made are equally applicable to energy dispersive spectrometry.

Trace Element Analysis of Rocks by X-ray Spectrometry

Undoubtedly the most important applications of X-ray fluorescence spectrometry (XRF) have been in the analysis of major elements where the technique provides a unique method of measuring the concentration of all elements having Z > 10 with extremely good precision in a wide range of matrices. However, XRF is in addition a powerful method for trace element analysis. In this discussion, the principles of the method for the trace element analysis of rocks are outlined, its capabilities are summarized, and the advantages and disadvantages of the technique are pointed out.

Industrial and environmental applications of X-ray fluorescence spectrometry. Role of X-ray fluorescence spectrometry in the plastics and petrochemical industry

The first page of this article is displayed as the abstract.

Industrial and environmental applications of X-ray fluorescence spectrometry. Exploiting energy dispersive X-ray fluorescence spectrometry for the determination of trace elements in geological samples

Industrial and environmental applications of X-ray fluorescence spectrometry. Exploiting energy dispersive X-ray fluorescence spectrometry for the determination of trace elements in geological samples

Some recent developments in the surface-analytical application of X-ray fluorescence spectrometry

Standard depth profiles of an analyte deposited into (diffusion or ion implantation) or on (thin-film deposition) a plane surface can be analyzed for profile type and centroid depth or film thickness by means of a standardless method in which the matrix-attenuated signals of the fiuorescing analyte measured at two different take-off angles are related to the mathematical distribution moments of the profile. For a binary thin film the element ratio can also be established. Results obtained on phosphorus profiles in silicon and on zinc sulphide optical coatings are referred to.

Application of x-ray fluorescence spectrometry for identification of unirradiated pebble-bed reactor fuel element

This paper deals with the investigation of the potential application of x-ray-fluorescence spectrometry for the identification of unirradiated fuel elements for the pebble-bed reactor. Measurements were carried out on graphite spheres impregnated with different chemical elements at various concentrations. The intensities of the K χ lines of these trace elements, as a function ofconcentration, were measured in order to establish the optimal concentrations needed for fuel-element identification, and the required sensitivity of the spectrometer employed. These measurements have shown that x-ray-fluorescence methods can be employed with advantage for identifying peeble-bed-reactor fuel elements. There are enough suitable chemical elements and a wide range of concentrations of each element, which may be used for this purpose.

Application of X-ray Fluorescence Spectrometry to the Study of the Marine Environment

Abstract The possibility of using X-ray techniques for the study of pollution of a marine ecosystem by heavy metals has been investigated. In this preliminary study data are reported, obtained on the concentrations of Cr, Cu, Fe, Mn, Ni, Pb and Zn of various samples of marine organisms, sediments and sea water which have been collected in the Mediterranean sea together with atmospheric particulates on the coast near La Spezia. Improvements in the analytical procedure are proposed.

Determination of toxic metals in blood by x-ray fluorescence spectrometry.

An application of X-ray fluorescence spectrometry for the analysis of various toxic metals (lead, cadmium, manganese, chromium, nickel, vanadium) in whole blood was studied, and two techniques for sample preparation (vacuum drying and nitric acid combustion) were compared. The acid combustion method appeared to be superior on the basis of the accuracy and precision of the determinations. The tungsten-target X-ray tube was suitable for determining manganese, nickel, and vanadium, the lowest limits of detection being 0.021 mug/ml, 0.035 mug/ml and 0.017 mug/ml, respectively, and the precisions being between 4.25 and 6.92%. The sensitivity and reproducibility for lead, cadmium, and chromium were unsatisfactory. A comparison between the recoveries of X-ray fluorescence and atomic absorption analyses demonstrated that the X-ray method is suitable for determining manganese, vandium, nickel, cadmium, and lead. The poor sensitivity of the X-ray method, however, restricts its practical use. For vandium the results obtained by X-ray fluorescence were superior to those measured by a colorimetric method. No significant differences were observed between the results of single component and multicomponent analyses at the metal concentrations usual in physiological and toxicological cases.