Particle-induced X-ray Emission Spectrometry Research Articles

In Situ Irradiation-corrosion Monitoring of Metals Exposed to Advanced Nuclear Reactor Coolants with Thick-target Particle-induced X-ray Emission Spectroscopy (PIXE).

In Situ Irradiation-corrosion Monitoring of Metals Exposed to Advanced Nuclear Reactor Coolants with Thick-target Particle-induced X-ray Emission Spectroscopy (PIXE).

Calibration of a PIXE system at Peking University

A method combining particle-induced X-ray emission spectrometry (PIXE) and elastic backscattering spectrometry (EBS) was used to calibrate the PIXE system at Peking University. The selected thin standard samples were typically 50 μg/cm2 and the thicknesses of two thick standard samples are 3 mm. The calibration of PIXE system was divided into the calibration curve measurement of thin standard samples and the external standard method of thick standard samples. Both thin and thick samples cover the commonly used PIXE X-ray energy range 1.4–18.0 keV. GUPIXWIN introduces an Instrument factor H to describe the calibration process. It is found that the measured H(Z) curve can be approximated as a Z-independent line with an average value of 3.30×10−4. The deviation of multiple measurements of a single element is between 0.42% and 4.75%. For thick samples, the incident particles are protons and 3He+, a H value of (4.97±0.01)×10−4 was obtained.

Characterization of agricultural biomass by particle induced x-ray emission and Rutherford backscattering techniques

Particle-induced x-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) techniques are non-destructive elemental analyses method with high sensitivity and capability for multi-element analysis in one spectrum. These techniques have not been used for the elemental characterization of biomass. So, this study characterized and evaluated elemental compositions of some selected agricultural biomass (Palm kernel shell (PKS), coconut shell (CS), cassava peel (CP), and Africa star apple seed shell (ASASS)) using combined PIXE and RBS. The results were compared with the ultimate analysis and optical-based techniques. Results from PIXE and RBS analysis confirm the presence of C, O, S, Na, Mg, P, Si, K, Ca, Fe, Cl, Al, Ti, Cu, and Zn in the tested biomass samples. Estimation of RBS accuracy by direct comparison with the ultimate analysis of some biomass samples showed a wide disparity of ±10.7% and ±2.57% in the RBS data for carbon and oxygen in PKS and a disparity of ±5.22% and ±0.55% in the RBS data for carbon and oxygen in coconut shell respectively. In the case of minor and trace element concentrations, estimated errors in the range of 1–3% and 2.68–4% were observed for optically based techniques compared with PIXE and RBS analysis, respectively.

A QUÍMICA ANALÍTICA APLICADA AOS ESTUDOS DE PIGMENTOS RUPESTRES: UMA REVISÃO

Instrumental advances have been employed in the study of archeological remains such as prehistoric rupestrians paintings with the objective of chemically characterizing them in order to reconstruct the cultural technologies of a prehistoric human group and/or to support conservation science studies. The analytical techniques most commonly used in archaeometric research are non-destructive or semi-destructive and preferably portable to preserve the integrity of the rupestrians paintings. They include X-ray Fluorescence Spectrometry (XRF), Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM/EDS), Raman spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Laser-induced Breakdown Spectroscopy (LIBS), and the many techniques with emerging applications such as Mössbauer Spectroscopy, X-ray Absorption Near Edge Structures (XANES), Particle Induced X-ray Emission Spectrometry (PIXE) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA ICP-MS). Therefore, this paper presents a review of the literature on the development of chemical strategies employed in the study of rock art, focusing mainly on the critical evaluation of analytical techniques used, limitations, challenges and the perspectives within this area of study

X-ray spectroscopy study of ancient glass beads at Hor-Ek, Thailand

In ancient time, it is well known that glasses have been used in ornament and decorative objects in Thailand for several hundred years as implied by archaeological evidences such as glass beads and decorative glasses. In this work, the blue and red colored glass beads selected from the Hor-Ek archaeological site in Nakhon Pathom province (central Thailand) have been characterized chemical composition using a scanning electron microscope coupled with energy dispersive X-ray spectroscopy (SEM-EDS) and a particle induced X-ray emission spectroscopy (PIXE). Cu-K-edge XANES (X-ray absorption near edge structure) of the selected samples is also carried out in fluorescent mode in order to determine the oxidation state. The results showed that the beads are all the LMHK-based glass (low magnesia, high potash). The red and blue tonalities are affected by copper with different oxidation states, and/or the summation of copper and cobalt. The shape and composition of these ancient glass beads are similar to those collected from other four sites in southern Thailand such as Khlong Thom, Phu Khao Thong, Nang Yon, and Thung Thuk and the foreign countries such as India, China, and Vietnam. These detailsindicate the long-distance trade and exchange network in ancient maritime.

Ion beam analysis (IBA) and instrumental neutron activation analysis (INAA) for forensic characterisation of authentic Viagra® and of sildenafil-based illegal products

Illegal trafficking of pharmaceutical products by criminal organisations is a global threat for public health. Drugs for erectile dysfunction such as phosphodiesterase type 5 inhibitors are the most commonly counterfeited medicines in Europe. The search of possible toxic chemical substances in seized products is needed to provide early warning for public health. Furthermore, the elemental profile of the seized products can be useful in criminal investigations. For the first time an ion beam analysis (IBA) procedure to characterise authentic Viagra® tablets and sildenafil-based illegal products is described. Moreover, results are compared with the ones obtained by instrumental neutron activation analysis (INAA) on authentic Viagra® tablets in two reactors. IBA results showed that a combination of particle-induced X-ray emission (PIXE) and secondary ion mass spectrometry using primary ions with energies in the range of several MeV (MeV-SIMS) is a powerful tool to characterise different products in a straightforward manner, allowing discrimination between legal and illegal products. INAA allowed accurate elemental quantification and also showed a great potential for the future implementation of an inter-laboratory classification system.

Exploration of Matrix Effects in Laser Ablation Inductively Coupled Plasma Mass Spectrometry Imaging of Cisplatin-Treated Tumors.

The use of a low aerosol dispersion ablation chamber within a laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) setup allows for high-resolution, high-speed imaging of the distribution of elements within a sample. Here we show how this enhanced capability creates new analytical problems and solutions. We report the distribution of platinum at the cellular level in non-small cell lung cancer (NSCLC) explant models after treatment with clinically relevant doses of cisplatin. This revealed for the first time a correlation between the platinum signal and the presence of carbon deposits within lung tissue. We show how complementary ion beam analysis techniques, particle-induced X-ray emission (PIXE) and elastic backscattering spectrometry (EBS), can be used to explore potential matrix effects in LA-ICP-MS data. For these samples, it was confirmed that the enhancement was unlikely to have resulted from a matrix effect alone. Thus, the presence of carbon deposits within tissue has potential implications for the effective distribution of the cisplatin drug.

Calculation of secondary electron bremsstrahlung in the binary encounter approximation using Dirac–Hartree–Fock–Slater velocity distributions

One of the main factors that determine the detection limit in particle-induced X-ray emission (PIXE) spectrometry is the continuous X-ray background. In the case of impinging protons, a complete description requires five radiative processes. Among them, secondary electron bremsstrahlung (SEB) is one of the largest contributions and describes the bremsstrahlung radiated by the electrons ejected from the target atoms by proton impact. The calculation of SEB cross sections in the binary encounter approximation (BEA) entails knowledge of the velocity distributions (VDs) of the atomic electrons. For this purpose, analytical hydrogenic VDs are currently used for all the (sub)shells. In the present work, numerical VDs calculated from Dirac–Hartree–Fock–Slater (DHFS) wave functions are employed. Additionally, a compact equation for the SEB differential cross section is derived. Results for the ionisation and SEB cross sections of Al, Ag, and Au calculated from the DHFS and hydrogenic VDs are compared in detail.

Particle Induced X-ray Emission spectrometry (PIXE) of Hawaiian volcanics: An analogue study to evaluate the APXS field analysis of geologic materials on Mars

The Alpha Particle X-ray Spectrometer (APXS), a field instrument onboard four martian rovers, measures largely unprepared, in situ samples on Mars. The APXS has high precision that enables the determination of elemental concentrations in a wide range of geologic materials. However, lack of sample preparation can lead to heterogeneous matrix effects, and understanding the associated uncertainty is essential for interpreting APXS data. Here we use Particle Induced X-ray Emission spectrometry (PIXE) to analyze a suite of geologic samples from Hawai'i as an analogue study to better understand APXS analyses of martian samples. Wavelength-Dispersive X-ray Fluorescence (WDXRF) analyses of fused glass beads establish higher-accuracy standards for the Hawaiian samples. Sulfate-silicate mixtures were made to evaluate sulfur analysis by PIXE. Results show that the PIXE concentrations for most major elements have 2–6% accuracy, which is comparable to the APXS. However, the PIXE concentrations are systematically high in Al and low in Mg, resulting in lower accuracy (13% and 20%, respectively). Olivine-phyric lavas and most of their altered products have the largest discrepancies with Al concentrations up to 25% high and Mg up to 35% low. Sulfur is systematically high (up to 30% in a basalt matrix) compared to gravimetric S concentrations in the sulfate-silicate mixtures. These systematic deviations in Mg, Al, and S are linked to heterogeneous matrix effects, because PIXE and APXS analyses assume all atoms in a sample to be homogeneously mixed on the sub-micrometer scale, which is not the case. Two key implications for APXS results are: (1) Olivine-bearing samples likely have reported concentrations of Mg that is too low and Al that is too high. Thus, olivine-phyric basalts in Gusev crater and the basaltic sand and soil at three landing sites may have Mg and Al concentrations closer to those of the olivine-phyric shergottites and modelled martian crust than previously thought. (2) Sulfate-silicate mixtures may have overestimated S concentrations reported, resulting in greater uncertainty in the stoichiometry of Ca-sulfates, which is used to deduce the geochemical associations of sulfur in samples.

PIXE Investigation of Ancient Linen Fabrics Dated from Old Kingdom to Ptolemaic Ages (2200-300 B.C.)

External milli-beam particle induced X-ray emission spectroscopy (PIXE) has been used as non-destructive technique to investigate ancient linen fabrics from pre-dynastic and Ptolemaic ages belonging to the archaeological collections of the Egyptian Museum of Turin and to the Civic Archaeological Museum of Bologna, Italy. 9 linen fabric samples dated from Old Kingdom to Ptolemaic ages (2200-300 B.C.) were investigated, as well as 5 modern linen fabric samples, added for comparison. The primary goal of this work has been to advance the correct material description of the fabrics providing scientific data for further and more comprehensive comparative analyses. PIXE has provided quantitative analyses for the major (Si, Cl, K, Ca and Fe) and minor or trace elements as P, Ti and Mn, supplying information on the near-surface elemental composition. The achieved results contribute to comprehend the structural basis for the chemical properties of the considered materials, as well as to set up a classification according to the chemical composition, allowing in general a better understanding of the studied linen cloths.

Performance and application of heavy ion nuclear microbeam facility at the Nuclear Physics Institute in Řež, Czech Republic

The Tandetron Laboratory of the Nuclear Physics Institute of the Czech Academy of Sciences is equipped with five beam lines associated with a 3 MV tandem electrostatic accelerator model 4130 MC from High Voltage Engineering Europa B.V. This accelerator is coupled with two duoplasmatron sources and a single sputter ion source and provides ions from hydrogen to gold. One of these lines is a nuclear microbeam facility, utilizing ion beams of micro- and sub-micro sizes for materials research by use of particle induced x-ray emission spectroscopy, particle induced gamma emission, Rutherford back-scattering spectroscopy, and scanning transmission ion microscopy methods as well as for ion beam writing. The major advantage of the presented microprobe is a possibility of 3D structure creation not only in polymer materials using light ions but also in other materials such as glass, ceramics, etc. by use of heavy ions. The focusing system allows focusing of charged particles with a maximum rigidity of 11 MeV amu/q2. The usual resolution in high and low current modes is 2 × 3 µm2 for a 100 pA and 0.3 × 0.5 µm2 for the 2000 ions/s of 2 MeV protons, respectively. A detailed facility description is given in the paper. The applications of focused beams of heavy ions as well as examples of light ions utilizing are also presented in the article.

Structure and morphology of copper oxide composite materials synthesized by the arc discharge method

Copper oxide is a semiconducting compound with a narrow band gap and is used for photoconductive and photothermal applications. Most of the synthesis methods for the preparation of copper oxide composite materials either are unsuitable for mass fabrication or inevitably introduce unwanted impurities. In this work, we report on the synthesis of copper oxide composite materials by the arc discharge method with a pure copper rod as the anode and graphite as the cathode. Ion beam analysis techniques, particle-induced X-ray emission and Rutherford backscattering spectrometry were used to probe the impurities in the copper oxide composites. Ion beam analysis results revealed copper and oxygen as constituent elements with no impurities. X-ray diffraction results discovered the presence of CuO, Cu2O and Cu phases in the composite materials. The morphology of the as-synthesized copper oxide was studied by scanning electron microscopy. Results clearly demonstrated that spherical particles were obtained with an average diameter of 14 [Formula: see text]m (range 2–85 [Formula: see text]m), 35 [Formula: see text]m (range 20–100 [Formula: see text]m) and 50 [Formula: see text]m (range 30–120 [Formula: see text]m) for the arc current of 60 A, 80 A and 95 A, respectively. It was found that the morphology can be controlled by the arc discharge parameters, e.g. a lower arc discharge current contributed to a smaller particle size. This is because the electric arc current influences the nucleation and the growth of the spherical structures. Due to its simplicity of synthesis, the proposed arc discharge is a promising technique for the fabrication of copper oxide composite materials for optical and electrical applications.

Geochemical characterization of soil samples from gold mining areas using PIXE spectroscopy.

Particle-induced x-ray emission (PIXE) spectroscopy has been used to characterize soil samples from two relatively old gold mine sites (Iperindo and Itagunmodi) in the Ilesha schist belt of Southwestern Nigeria. This is with a view to identifying the indicator or pathfinder elements of gold for fingerprinting and toxicity potential assessment purposes. Average elemental concentrations of 19 major, minor, and trace elements were determined, and the geochemical data of Mn, Ni, Cu, Zn, Ag, As, Pb, and Au together with multivariate factor and cluster statistical analyses allowed to identify As and Ag as the pathfinder elements of gold. The high concentration of the determined pathfinder elements (As and Ag) as well as other toxic metals (Pb and Cu) implies a relatively high metal contamination risk to the miners and the ecosystem. The major hazard is represented by the abandoned mining wastes, pits, and ponds, already serving as fish ponds.

Elemental characterization of gold-plated costume jewelry using particle-induced X-ray emission

Nine gold-plated costume jewelries bought in the street market of Porto Alegre and from Chinese websites were investigated through Particle-Induced X-ray Emission (PIXE) and Rutherford Backscattering Spectrometry (RBS) in order to verify their elemental composition and distribution. The analyzed costume jewelries were made of Cu-based alloys with Ni, Zn, Sn and Al. Elements such as Ag, Al, Bi, Cd, Co and Fe were found in minor amounts in some particular samples. Through RBS, it was possible to distinguish the bulk from the gold-plated layer. Toxic elements as Ni and Cd were found in at least one sample. The high concentration of Ni comes from the bulk Cu-alloy below the Au layer. In this case, the Au acts as a protective layer separating the Ni from the user’s skin.

Characterization and application of in-vacuum PIXE/EBS system for the direct elemental analysis of thick solid biological samples

Utilization of combined particle-induced X-ray emission (PIXE) and elastic backscattering (EBS) spectrometry for the direct elemental analysis of thick solid biological samples was thoroughly discussed. Powdered samples pressed as pellets were directly analyzed. Combination of applying low ion beam currents, random scanning of the sample across the beam during data acquisition, and using special sample holder enabled effective minimization of local ion beam heating. This subsequently inhibited potential element loss during ion beam irradiation. Matrix elements were determined from multiple EBS spectra, which were acquired using three different ion beam energies. Subsequently, averaging of the elemental concentrations obtained was achieved using novel MultiSIMNRA software. Moreover, combined EBS spectrometry, nuclear reaction analysis (NRA), and elastic recoil detection analysis (ERDA) measurements were used to overcome the limitations of using EBS separately and subsequently obtain accurate matrix element concentrations. The validity of the PIXE/EBS system for the direct elemental analysis of thick biological samples was comprehensively evaluated. The obtained concentration values demonstrated reliable results for most investigated elements (5–15%), starting from sodium onwards. The non-satisfying results were evaluated and justified.

Mercury Contamination of Cattle in Artisanal and Small-Scale Gold Mining in Bombana, Southeast Sulawesi, Indonesia

The industrial mining sector is one of the main contributors to environmental damage and toxic metal pollution, although some contamination originates from natural geological sources. Due to their position at the top of the food chain, cattle tend to bioaccumulate mercury (Hg) in their bodies. We used analyses of cattle hair samples to investigate Hg contamination in cattle farmed within and outside of an artisanal and small-scale gold-mining area in Bombana, Southeast Sulawesi, Indonesia. We also examined the factors that might have influenced the toxicity, such as the environmental conditions, sex, and age of the cattle. A total of 63 hair samples were analyzed by particle-induced X-ray emission spectrometry. The mean Hg concentration was significantly higher in hair from cattle farmed within the artisanal and small-scale gold mining area (11.44 μg/g hair) than in those farmed outside the area (2.89 μg/g hair, p < 0.05). A possible cause of this is contamination by mercury persistent in terrestrial food chain. The results indicates that the level of toxic metals such as Hg need to be controlled in food sources to protect human health, especially in Bombana, Indonesia.

Neutron based archaeometallurgical investigation of Picenan and Roman age metal objects from the Academia Georgica Treiensis collection (Italy)

ABSTRACTNon-destructive prompt gamma activation analysis (PGAA), neutron radiography (NR) and high resolution time-of-flight neutron diffraction (TOF-ND) have been applied to investigate metal archaeological artefacts belonging to the Academia Georgica Treiensis (AGT) collection. 8 archaeological items have been analysed, by using the facilities of the Budapest Neutron Centre (BNC). Some of these objects mostly dating back probably to the VI-IV century B.C. and presumed to be discovered in the Marche Region, Italy. The primary goal of the analyses was to advance the correct technological and material description of the objects, providing scientific data for further and more comprehensive comparative analyses also covering the find material from the close archaeological sites.The neutron investigations allowed determining the bulk composition, also providing either a qualitative and quantitative assessment of the phase composition and the structural properties of the constituents, or radiographic images, which would finally help to identify possible manufacturing techniques.Additional examinations, carried out by external milli-beam particle induced X-ray emission spectroscopy (PIXE), provided quantitative analyses of major and trace elements (e.g., Fe, Pb and As) in order to recognize the constitutive alloys and to supply information on the near-surface elemental composition, complementary to the data characteristic for the bulk.The obtained results, thought to be useful to set up a classification according to the chemical composition, and this way allow achieving important information related to the possible provenance of the objects.

High level leaching of heavy metals from colorful ceramic foodwares: a potential risk to human.

Ceramic foodwares are among the products used by people on daily basis without being cautious of exposures to heavy metals through possible leaching from the glaze ceramics. This study investigated the levels of heavy metals found in some commonly used ceramic foodwares in Nigeria with the aim of determining levels of human exposures through the use of the ceramics. To achieve this, acid digestion was carried out for the total metal concentrations and leaching tests were done using 4% acetic acid as a leaching agent. Metal concentrations were quantified using flame atomic absorption spectrometry (FAAS) and particle-induced X-ray emission spectrometry (PIXES) analysis. All the ceramic foodwares studied were found to contain varied amounts of heavy metals in their glazes, with concentrations in the range of 26.45-2071.46, 5.20-547.00, 1.24-2681.02, 2590.00-8848.40, 6.42-654.66, 112.69-649.95, 63.38-2518.51, and 3786.51-8249.44μgg-1 for Pb, Cd, Zn, As, Cu, Cr, Mn, and Fe, respectively. Concentrations of the metals leached from the ceramics were in the range of 0.11-0.97, 0.01-0.28, 0.00-4.19, 1.93-15.00, 0.01-0.41, 0.09-0.60, 0.01-2.14, and 0.01-11.53mgL-1 for Pb, Cd, Zn, As, Cu, Cr, Mn, and Fe, respectively. Comparing the ratio of the metals leached from the ceramic wares with those of the metal oxides in the ceramics, it was noticeable that not all the metals detected in the ceramic samples were domiciled in the glaze but in the clay materials used for the ceramics.

Analysis of elements in lake sediment samples by PIXE spectrometry

This work aims to determine the concentrations of several elements (e.g. Pb, Ni, Zn, Mn, Cr, and Fe) from lake sediments, in order to characterize their origin and evolution. Particle Induced X-ray Emission (PIXE) technique using the 3MV Tandetron™ particle accelerator from National Institute for R&D in Physics and Nuclear Engineering “Horia Hulubei” (IFIN-HH), Magurele-Bucharest, Romania, was applied. Sediment cores from different salt lakes from Romania (i.e. Amara Lake, Caineni Lake, and Movila Miresii Lake) were collected, in August 2015. The content of Pb, Cr, Mn, Fe, and Ni from sediment samples show similarities with other data presented in literature and international regulation. The Zn was the only element with a higher content in all samples (e.g. maximum 401.7–517.3mg/kgd.w.).

Current Mercury Exposure from Artisanal and Small-Scale Gold Mining in Bombana, Southeast Sulawesi, Indonesia-Future Significant Health Risks.

The rapid expansion of the artisanal and small-scale gold mining (ASGM) industry in developing countries has marginalized the local communities in poverty, and resulted in occupational exposure to mercury via the gold extraction process. We investigated the mercury exposure of the mining workers lived inside and outside the mining area. Based on the occupations of the contributors, the hair samples were divided into three subgroups: directly exposed, indirectly exposed, and a control. A total of 81 hair samples were analyzed by particle-induced X-ray emission spectrometry. The median mercury concentration was highest in the hair from the directly exposed group (12.82 μg/g hair) (control group median: 4.8 μg/g hair, p < 0.05), and the concentrations in hair from 45 respondents exceeded the Human Biomonitoring I (HBM I) threshold limit. Mercury concentrations were also elevated in the hair from the indirectly exposed group (median 7.64 μg/g hair, p < 0.05), and concentrations in hair from 24 respondents exceeded the HBM I threshold limits. Exposure to mercury during ASGM presents health risks and is harmful for the miners; mercury is also at hazardous levels for people who live in the mining area but who are not engaged in mercury-based gold extraction.