Particle Induced X-ray Emission Analysis Research Articles

PIXE and RBS analysis of Tl-1223 superconducting phase substituted by scandium

Ion beam analysis techniques (IBA) were performed to determine the elemental stoichiometry of superconducting samples of type TlBa 2Ca 2− x Sc x Cu 3O 9− δ , with 0 ⩽ x ⩽ 0.6, prepared via solid-state reaction technique. By combining particle induced X-ray emission (PIXE) with Rutherford backscattering spectrometry (RBS), the stoichiometry of the samples is determined. However, the oxygen content is obtained by using non-Rutherford backscattering cross-section at 3 MeV proton beam. Furthermore, the prepared samples were also characterized using X-ray powder diffraction (XRD) and electrical resistivity measurements. The X-ray data indicate that the partial substitution of Ca 2+ by Sc 3+ ions does not affect the tetragonal structure of Tl-1223 superconducting phase. The superconducting transition temperatures T c, determined from electrical resistivity measurements, was found to be highly correlated to the Sc-content.

Characterization of urban aerosol in Campinas, São Paulo, Brazil

A quantitative study was performed in Campinas, Brazil. Measurements were taken on an avenue with intense vehicle traffic in the city's downtown area from August 2003 to August 2004. A dichotomous sampler was employed for PM 2.5 and PM 10. Samples were collected for 24 h at 3-day intervals. In addition, seasonal variations were investigated, using a MOUDI cascade impactor and VOC adsorption tubes, during a specific 5-day period in the summer of 2003 (December) and the winter of 2004 (August). The polycarbonate filters were analyzed by gravimetry, Particle Induced X-ray Emission (PIXE), ion chromatography and reflectance, to identify the mass concentration, elemental composition, ions and elemental carbon mass, respectively. The quartz filters were analyzed by gravimetry and thermal combustion carbon analysis to identify the mass concentration and carbon mass. Results showed an annual mean of 20.85, 10.68 and 10.17 μg m − 3 for PM 10, PM 2.5 and PM 2.5–10, respectively. The cascade impactor provided mass distribution and revealed differences between the two seasons. The size distribution for chemical elements indicated soil-derived elements in the coarse fraction. PM winter concentrations were expected to be higher than those in summer, but that was not the case during the days of this study, when summer and winter concentrations were almost identical The PIXE analysis revealed metals and metal compounds, soil-derived elements, sulfates, carbonates, chlorides and other anthropogenic air-borne particles, supposing molecules in their usual composition. An analysis of the VOCs revealed benzene, toluene, m, p-xylene, n-hexane, 2-metilhexane and n-nonane. A mass balance analysis indicated different classes, among which elemental carbon was the most abundant, followed by organic carbon, soil elements and industrial sources.

Determination of the metal balance shift induced in small fresh water fish by X-ray irradiation using PIXE analysis

The balance of essential elements in organisms can be changed by environmental stresses. A small fresh water fish, the medaka, was irradiated with X-rays (total dose: 17 Gy, which is not a lethal dose for this fish). Essential elements in the liver, gall bladder, kidney, spleen, heart and brain of the fish were measured by the particle induced X-ray emission (PIXE) method and compared with those of a control fish. Various changes in the elemental balance shift were observed. The PIXE method can analyze many elements in a small sample simultaneously, and so the changes in elemental content induced by irradiation were readily determined.

PIXE analysis of some medicinal plants used in cleaning teeth in southwestern Nigeria

Sixteen medicinal plants used for cleaning teeth in southwestern Nigeria were analyzed using the particle-induced X-ray emission (PIXE) technique. These medicinal plants have other therapeutic uses, but the emphasis and main focus were on their beneficial effects on human teeth. PIXE measurements were carried out using 1.8 MeV collimated proton beam from the 2.5 MV AN 2000 Van de Graaff accelerator at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Padova Italy. The results showed the presence of 18 different elements at different concentrations, 2 plants had traces of gold, and none of the plants contained any toxic heavy metals. The metabolic roles of the detected elements were discussed especially as they affected the formation, growth, development, and protection of human teeth. The results of this study are presented and discussed.

Calcium Distribution in the Vessel Wall and Intima-Media Thickness of the Human Carotid Arteries

Increased common carotid artery (CCA) intima-media thickness (IMT) measured by B-mode ultrasound is an early marker of the atherosclerotic process. Arterial calcification is not clearly understood. Using the particle-induced X-ray emission (PIXE) method, we have looked for the location in the artery wall where calcium accumulated in the early phase of atherosclerosis. Twelve segments of CCAs of deceased stroke patients were investigated. In-vivo, carotid duplex ultrasound was performed with bilateral CCA IMT measurement at plaque-free sections. During autopsy, segments of carotid arteries were collected and filled under pressure with a stained histologic embedding material. The frozen arteries were cut into 60-μm-thick slices. Calcium distribution maps from the segments of arteries were determined by PIXE method. IMT measured by ultrasound and calcium distribution maps measured by PIXE were compared. In our cross-sectional study, using the PIXE analysis and ultrasound images, we could demonstrate early calcium accumulation in the media layer. Our results have also shown a significant relationship between calcium content of distributional maps measured by PIXE analysis and corresponding IMT on B-mode ultrasound images of human CCAs. (E-mail: tundus@dote.hu)

Trace element concentrations from São Francisco River - PR analyzed with PIXE technique

Analysis of trace elemental concentration in the water of the Sao Francisco River located in the western part of the Brazilian state, Parana, has been carried out using particle induced X -ray emission (PIXE) technique. The main objective of this work was to characterize and to monitor trace elements in the water of the Sao Francisco River, as well as to provide valuable information about the levels of metallic ion pollutants. Due to the detection limit s of the PIXE analysis, up to 10 elements were quantified. Present work is a first attempt to identify trace elements of the Sao Francisco River. The highest total concentrations of Cr, As, Cu and Zn, detected in the river water are above the limits recomm ended by the Brazilian Environmental Legislation. The occurrence of these elements above the prescribed limits indicates the necessity of using improved techniques for industrial waste treatment.

Characterisation by PIXE–RBS of metallic contamination of tissues surrounding a metallic prosthesis on a knee

Implants used as biomaterials have to fulfill conditions of functionality, compatibility and sometimes bioactivity. There are four main families of biomaterials: metals and metal alloys, polymers, bioceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. This debris may develop toxicity, inflammation and prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters influencing the tissue responses.In this paper, we characterised metallic contamination produced by knee prosthesis, composed with TiAl6V4 or Co–Cr–Mo alloys, into surrounding capsular tissue by depth migration, in vivo behaviour, content, size and nature of debris by PIXE (Particle Induced X-ray Emission) method associated with RBS (Rutherford Backscattering Spectroscopy).Debris distribution in the whole articulation is very heterogeneous. Debris migrates several thousand micrometers in tissues, with a characteristic decrease. Solid metallic particles of about micrometer size are found in the most polluted samples, in both alloys TiAl6V4 and Cr–Co–Mo. In the mean volume analysed by PIXE, the concentration mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TiAl6V4 debris and show the chemical evolution of Cr–Co–Mo debris.Development of a protocol to prepare thin targets permits us to correlate PIXE and histological analysis in the same zone. The fibrous tissue (collagen fibres, fibroblasts) and macrophage cells are observed with optical microscope in polluted areas. This protocol could locate other pathologies in ppm contamination range, thanks to the great sensitivity of the PIXE method.

PIXE analysis on Maya blue in Prehispanic and colonial mural paintings

Particle induced X-ray emission (PIXE) experiments have been carried out at the AGLAE facility (Paris) on several mural samples containing Maya blue from different Prehispanic archaeological sites (Cacaxtla, El Tajín, Tamuin, Santa Cecilia Acatitlán) and from several colonial convents in the Mexican plateau (Jiutepec, Totimehuacán, Tezontepec and Cuauhtinchán). The analysis of the concentration of several elements permitted to extract some information on the technique used for painting the mural, usually fresco. Principal component analysis permitted to classify the samples into groups. This grouping is discussed in relation to geographic and historic data.

Trace-element analysis of Steller sea lion (Eumetopias jubatus) teeth using a scanning X-ray analytical microscope

Marine mammals are top predators in marine ecosystems and bioaccumulate various trace elements that pass through the food web (Miles and Hills 1994; Wagemann and Stewart 1994; Dietz et al. 1996). Trace elements include both essential and non-essential metals. Iron (Fe) and zinc (Zn) are essential metals that occur widely and abundantly in living organs. The concentrations at which they occur in an animal are affected not only by the diet, age, nutritional stress but also health status of the animal. In mammals, it is possible to examine element accumulation using their teeth. During dentine formation, trace elements are removed from dietary and environmental sources, and incorporated into the crystalline apatite structure of the teeth. Here, unlike in bones, they are not subject to reabsorption or remodeling, so they can be used to examine an animal’s life history. Ando et al. (2005) found significant long-term differences in Zn/calcium (Ca) and Fe/Ca ratios from 1968 to 1999 by particle-induced X-ray emission analysis (PIXE). And Zn/Ca and Fe/Ca ratios were higher in younger males than older males, but showed no trend with age in females. There are question about fluctuation of these metals within each animal. In this study, we examined the canine teeth of Steller sea lions (Eumetopias jubatus) to assess their action and the fluctuation of essential metals of that occur in the teeth with their each life history.

Design and Calibration of a Multi-Channel Aerosol Sampler for Tropopause Region Studies from the CARIBIC Platform

An aircraft-based, multi-channel aerosol sampler for studies of the upper troposphere and lowermost stratosphere from the CARIBIC (Civil Aircraft for Regular Investigation of the Atmosphere Based on an Instrument Container) platform was designed and calibrated. The sampler operates with an impaction technique at a flow rate of 10.4 lpm and consists of sixteen sampling channels. Samples are collected in a time sequence. Each channel contains two sample types that are used for quantitative measurement of concentrations, using particle-induced X-ray emission (PIXE), and single particle analysis with electron microscopy. The minimum detection limits for PIXE analysis after 1.5 h sampling are, for example, 2.0, 0.14, and 0.02 ng/m3 STP (standard temperature and pressure) for sulfur, potassium, and nickel. Calibration included penetration studies of a cyclone arrangement used to define the upper size limit in the sampling to 2.0 μ m diameter and the collection efficiency of the impactor. Both components of the sampling system showed penetration and collection efficiency close to 100%, respectively, in the particle size range of interest. The impactor cut-off was found to be dependent on the ratio of the impactor upstream-to-downstream pressure for ratios well below the critical pressure drop (i.e., the pressure where the jet reaches sonic velocity) being 0.15 μ m and 0.08 μ m for ratios 0.41 and 0.2.

Simultaneous PIXE and RBS data analysis using Bayesian inference with the DataFurnace code

The Rutherford backscattering spectroscopy (RBS) and particle induced X-ray emission (PIXE) techniques can be used to obtain complementary information about the characteristics of a sample but, traditionally, a gap has separated the available computer codes for analyzing data from each technique, being hard to simultaneously analyze data from the same sample. The recent development of a free and open source library, LibCPIXE, for PIXE simulation and analysis of arbitrary multilayered samples, has permitted to integrate this technique into the DataFurnace code which already handles many other IBA techniques such as Rutherford and non-Rutherford backscattering, elastic recoil detection and non-resonant nuclear reaction analysis. The fitting capabilities of DataFurnace can therefore now be applied to PIXE spectra as well, including the Bayesian inference analysis and the simultaneous and coherent fitting of multiple spectra from different techniques. Various examples are presented in which the simultaneous RBS and PIXE analysis allows us to obtain consistent results that cannot be obtained by independent analysis of the data from each technique.

Detection and quantitative determination by PIXE of the mutagen Sn2+ in yeast cells

The main goal of this work was to determine the concentration of Sn2+ ions in cells of the yeast Saccharomyces cerevisiae and to correlate their quantity with the genotoxicity of intracellularly accumulated metal ions. The intracellular metal content of yeast cells was determined by PIXE (particle-induced X-ray emission) after cell exposure to SnCl2. To that end, a thick target protocol was developed for PIXE analysis. The samples were irradiated with a 2MeV proton beam, while the induced X-rays were detected with a high-purity germanium detector. The results of the toxicity of SnCl2 and the PIXE analysis performed with two different yeast strains (haploid and diploid) suggest that the exposure of haploid and diploid yeast to Sn2+ induces DNA lesions and that the absorption depends on the genetic background of each strain.

Air pollution studies using PIXE and ICP methods

In the present work the moss biomonitoring technique and the combination of two analytical techniques - Particle Induced X-ray Emission (PIXE) [3] and Inductively Coupled Plasma (ICP) [4] - were applied for assessing environmental situation from the point of view of air polluting along the transect from north to south of the Dambovita County. PIXE analysis at the Tandem Accelerator FN-8 of the National Institute of Nuclear Physics - Horia Hulubei of Magurele, Bucharest, allowed determination of P, S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, As, Sr, Cd and Pb in samples. ICP analyses were made using a Baird ICP2070 - Sequential Plasma Spectrometer in Targoviste and we determined in samples the concentration of Li, B, Na, and Mg together with Cd and Pb. The obtained results will permit to determine the regional extent of heavy metals and toxic elements atmospheric pollution and to identify specially affected areas and local sources of

Particle-induced X-ray emission analysis of Eastern Indian ferromanganese oxide ores

Ferromanganese oxide ore samples were studied from four different mines by particle-induced X-ray emission (PIXE) technique using 3 MeV proton beam obtained from a 3 MV pelletron accelerator at the Institute of Physics, Bhubaneswar, India. After irradiation, the spectral data were analyzed by a GUPIX-2000 software. Large number of major, minor and trace elements have been estimated in these samples. It has been observed that there is a positive correlation among manganese and some elements like Ca, Co, Pb, Zn and Se, whereas V and Mo correlates with iron well.

Particle-induced X-ray emission analysis of Eastern Indian ferromanganese oxide ores

Particle-induced X-ray emission analysis of Eastern Indian ferromanganese oxide ores

Structural, optical and compositional studies of stepwise flash evaporated CuIn 3Te 5 films

CuIn 3Te 5 films were grown by stepwise flash evaporation from powder CuIn 3Te 5 source. X-ray diffraction and particle induced X-ray emission analyses confirmed the phase purity and compositional homogeneity of the source material. Transmission electron microscopy studies showed that CuIn 3Te 5 films are single-phase and polycrystalline in nature. Rutherford backscattering spectrometry studies revealed that the films are near stoichiometric. Optical transmittance analysis yielded a band gap of ∼1.03 ± 0.02 eV for CuIn 3Te 5 films, which is in close agreement with the value reported for bulk CuIn 3Te 5.

APPLICATION OF PIXE FOR A MULTI-ELEMENT ANALYSIS OF MARINE PHYTOPLANKTON TOWARDS THE DEVELOPMENT OF A NEW BIOLOGICAL ASSESSMENT METHOD FOR HEAVY METAL POLLUTION

Particle-induced X-ray emission (PIXE) was applied for the determination of heavy metals accumulated in natural phytoplankton. We selected four Japanese marine sites to collect phytoplankton: Toni Bay and Kamaishi Bay (Kamaishi, Iwate) as non-polluted areas; and Shimotsu port (Shimotsu, Wakayama) and Toyama new port (Shinminato, Toyama) as polluted areas. After removing the zooplankton and visible dust by passing the seawater through an NXX13 plankton net (95-μm mesh aperture), the phytoplankton were collected on a polycarbonate filter (25 mm diameter, 1.0 μm pore size) by suction filtration. The filter was dried and subjected to scanning electron microscopy (SEM) and a PIXE analysis. The phytoplankton consisted of diatoms, dinoflagellates and coccolithophores were observed by SEM analysis on the filter prepared from 100 ml of Toni Bay seawater. Heavy metals ( Pb , Ni , Cu , Cr , Zn , Mn , Hg and As ) could be detected by the PIXE analysis in almost all the cases tested, in which 50-200 ml each of respective seawater sample was filtered. There was a linear relationship between the amount of heavy metals on the polycarbonate filter (ng cm-2) and the volume of seawater (25-200 ml) filtered (i.e. the amount of phytoplankton collected on the filter). Likewise, the PIXE analysis revealed that significant differences in heavy metal contamination between the polluted and non-polluted areas, and also among sampling sites in a polluted area depending on the location and seawater movement. These results indicate that a multi-element analysis of marine phytoplankton by PIXE would be a promising technique for biologically assessing and monitoring heavy metal pollution in the first link of the aquatic food chain.

Influence of orange juice in the levels and in the genotoxicity of iron and copper

World consumption of natural juices is increasing as a consequence of the human search for a healthier life. The juice production industry, especially for orange juice, is expanding in several countries and particularly in Brazil. Despite scientific data reporting beneficial properties derived from juice consumption, some components of juices have been identified as mutagenic or carcinogenic. Carcinogenic or genotoxic effects may be mediated by the interaction of juice components with transition metals or by sub-products of juice auto-oxidation. In this study, the mutagenic potential of orange juice and two metallic agents used in dietary supplementation, FeSO 4 and CuSO 4, were investigated using the comet assay in mouse blood cells (in vivo). Both metal compounds were genotoxic for eukaryotic cells after 24 h treatment at the doses used. Significant damage repair was observed after 48 h of treatment with the same compounds. Orange juice had a modulating effect on the action of metallic sulfates. In the case of iron treatment, the presence of the orange juice had a preventive, but not restorative, effect. On the other hand, in the case of copper treatment, the effects were both preventive and restorative. PIXE (particle induced X-ray emission) analysis indicated a positive correlation between DNA damage and the hepatic levels of iron and a negative correlation between whole blood copper and DNA damage. A negative correlation between hepatic iron and whole blood copper content was also seen in the treatment with both ferrous and cupric sulfates.

Electron beam evaporated molybdenum oxide films: a study of elemental and surfacemorphological properties

Thin films of transition metal oxides are very important in electrochromic applications. Molybdenumoxide (MoO3) thin films were prepared by using one of the physical vapour depositionsof the electron beam evaporation technique in a vacuum of the order of10−6 mbar. The detailed elemental analysis of the films was performed by a particle-inducedx-ray emission (PIXE) study and the nanosurface nature of the films was studied by usingan atomic force microscopy (AFM) analysis. To the best of our knowledge this is the firsttime PIXE analysis has been used for the elemental studies of electron beam evaporatedMoO3 films.

Trace element concentration in São Francisco River water using STXRF and PIXE techniques

Trace element concentrations in water from Sao Francisco River using Particle Induced X-ray Emission (PIXE) and Synchroton Total Reflection X-ray Fluorescence (STXRF) techniques are measured. The main objective of this work was to characterize and to monitor the trace elements in the water of Sao Francisco River, as well as to provide valuable information about the levels of metallic ions pollutants. Water samples were collected monthly at five locations along the course of the river from July 2003 to April 2004. As an internal standard, 11.6 ppm of Yttrium was added to 10 ml of the water sample. The PIXE and TXRF measurements were performed at the Ion Beams and Materials Laboratory (LAMFI) and the Brazilian National Synchrotron Light Laboratory (LNLS), using a proton beam and a polychromatic X-ray beam, respectively. Si(Li) detectors were used to collect the X-ray spectra. Due to the excellent detection limits of the PIXE and STXRF analysis, up to 15 elements were quantified. The highest total content of Cr, As, Cu and Zn detected in river water are above the limits recommended by the environmental legislation.