Particle Induced X-ray Emission Technique Research Articles

PIXE analysis of Thaumatococcus danielli in Osun State of Nigeria

Particle-induced X-ray emission (PIXE) technique was employed for the determination of elemental compositions of Thaumatococcus danielli (T. danielli) {Marantaceae} (Benn.) Benth [miraculous berry] in Osun State of Nigeria. The objective is to show the usefulness of T. danielli and especially the beneficial effects of the mineral concentrations from the leaves and fruits of T. danielli. The results show the detection of seventeen elements at different concentrations, and their beneficial effects to humans were discussed.

Element analysis of the eutardigrades Richtersius coronifer and Milnesium cf. asiaticum using Particle Induced X-ray Emission (PIXE)

Semi-terrestrial tardigrades are well-known for their tolerance to a variety of environmental extremes, including desiccation, freezing and radiation. Despite several attempts to reveal the genetic and molecular mechanisms behind the resilience of tardigrades, it is still unknown how these animals are able to maintain the integrity of their cellular components under severe stress. Quantitative or qualitative changes in molecular compounds (e.g., carbohydrates, proteins) are expected, and have been the main line of research towards understanding the tolerance of tardigrades. In radiation tolerant bacteria, a tolerance mechanism based on manganese has been proposed. We evaluate this hypothesis in tardigrades and provide the first data on element composition in desiccated and non-desiccated specimens of two eutardigrade species, Richtersius coronifer and Milnesium cf. asiaticum. A focused 2 MeV proton microbeam was utilised to determine the elemental content, distributions and concentrations, using the ion beam analytical technique particle induced X-ray emission (PIXE). The presence of six elements - phosphorus, sulphur, chlorine, potassium, calcium and iron - were confirmed in all tardigrade specimens, at levels up to a few mg g(-1). However, manganese was found in less than 10% of the analysed specimens, and in low amounts, thus our study provides no evidence for the manganese hypothesis. We also show that the distributions and/or concentrations of some elements differ between the two species as well as between the dehydrated and hydrated state. In particular, very low levels of iron were found in dehydrated M. cf. asiaticum. Our analysis shows that the PIXE technique is a useful tool for investigating questions on the distribution of elements both in dehydrated and hydrated tardigrades.

Composition and Morphology of Particle Emissions from in-use Aircraft during Takeoff and Landing

In order to provide realistic data for air pollution inventories and source apportionment at airports, the morphology and composition of ultrafine particles (UFP) in aircraft engine exhaust were measured and characterized. For this purpose, two independent measurement techniques were employed to collect emissions during normal takeoff and landing operations at Brisbane Airport, Australia. PM1 emissions in the airfield were collected on filters and analyzed using the particle-induced X-ray emission (PIXE) technique. Morphological and compositional analyses of individual ultrafine particles in aircraft plumes were performed on silicon nitride membrane grids using transmission electron microscopy (TEM) combined with energy-dispersive X-ray microanalysis (EDX). TEM results showed that the deposited particles were in the range of 5-100 nm in diameter, had semisolid spherical shapes and were dominant in the nucleation mode (18-20 nm). The EDX analysis showed the main elements in the nucleation particles were C, O, S, and Cl. The PIXE analysis of the airfield samples was generally in agreement with the EDX in detecting S, Cl, K, Fe, and Si in the particles. The results of this study provide important scientific information on the toxicity of aircraft exhaust and their impact on local air quality.

Assessment of heavy metal content and DNA damage in Hypsiboas faber (anuran amphibian) in coal open-casting mine

The aims of the study were to determine the heavy metal content in the tissues of Hypsiboas faber from a coal mining area and to compare the DNA damage in the blood cells of these animals with that of animals living in an unpolluted area. The heavy metal content was detected according to the technique of Particle-Induced X-ray Emission (PIXE) and the DNA damage was assessed by the Comet assay. Our results reveal that the specimens of H. faber collected from the coal mining area exhibited elements of order Fe>Cu>Al>Zn>Rb>Mn>Br, independently of the organ. The values of Comet assay parameters (DNA damage index and DNA damage frequency) were significantly higher in specimens collected from the coal mining area than in the reference animals. Our study concludes that the coal mining residues are genotoxic to amphibians and may have adverse effects on soil, water, vegetation and wild animals.

Surface interactions of a W-DLC-coated biomedical AISI 316L stainless steel in physiological solution

The corrosion stability of a W-DLC coated surgical AISI 316L stainless steel in Hanks' solution has been evaluated. Particle induced X-ray emission (PIXE) measurements were performed to evaluate the incorporation of potentially bioactive elements from the physiological solution. The film structure was analyzed by X-ray diffractometry and micro-Raman spectroscopy. The wear behavior was assessed using the sphere-on-disc geometry. The in vitro biocompatibility of the W-DLC film was evaluated by cytotoxicity tests. The corrosion resistance of the stainless steel substrate decreased in the presence of the PVD layer. EIS measurements suggest that this behavior was closely related to the corrosion attack through the coating pores. PIXE measurements revealed the presence of Ca and P in the W-DLC film after immersion in Hanks' solution. This result shows that the PIXE technique can be applied to identify and evaluate the incorporation of bioactive elements by W-DLC films. The film showed good wear resistance and biocompatibility.

Portable energy dispersive X-ray fluorescence spectrometry and PIXE for elemental quantification of historical paper documents

We have used a portable energy dispersive X-ray fluorescence spectrometer based on a silicon drift detector for elemental quantification of a historical paper document. Quantitative calculations were carried out using the WinAxil software package. In order to minimize matrix effects and to accurately reflect the conditions under which quantification is usually performed, the fundamental parameters package with a known paper samples was used. Reference values for paper samples were obtained through a set of a particle induced X-ray emission techniques.

Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings

The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.

Determination of Pb, Zr, Ti, Sr, Cr, Nb and La in lead zirconate titanate ceramics by particle‐induced X‐ray emission

A particle‐induced X‐ray emission (PIXE) technique has been used in the determination of the principal components Pb, Zr and Ti and the substituting elements Sr, Cr, Nb and La in lead zirconate titanate ceramics. In general, precision of analysis was concentration dependent from each element under study. For Pb, precision varied between 0.13% and 0.16%, at higher concentration of 59.32–64.5%. It was around 6–9% for Sr, Cr and Nb at concentrations of 1% or lower. Particular attention was devoted to the estimation of the analysis trueness. With this purpose, three methods were applied: (1) comparison of PIXE and inductively coupled plasma optical emission spectrometry concentrations, (2) recovery study and (3) comparison with a laboratory standard. Trueness of analysis was around 100 ± 10% for the evaluated elements Pb, Zr, Ti, Sr and Cr. The expected stoichiometry and elemental composition homogeneity of a wide group of produced ceramics were confirmed by the PIXE technique. Copyright © 2012 John Wiley & Sons, Ltd.

DETERMINATION OF MINING ACTIVITY OF RIVER SEDIMENTS OF THREE CHILEAN BASINS BY PARTICLE INDUCED X-RAY EMISSION (PIXE)

Mining is one of the most important industrial activities in Chile and there is growing concern on pollution by some mining and metallurgical processes. We have studied the contents of heavy metals in sediments from three river basins in Chile. Samples were collected based on hydrologic criteria in six sites along the rivers in their path from the Andes to the Pacific Ocean. Particle induced X-ray emission (PIXE), was used to determine elemental concentrations, and enrichment factors were used to evaluate the significance of anthropogenic sources. The results indicate the presence of Si, Al and Fe as major components. Cu, Cr, Mn, Pb and Zn are the main trace elements. In the Aconcagua river basin, which has less mining activity, the elemental concentrations are within the range of normal crust. Instead, samples from Choapa and Cachapoal river basins present high enrichment factors, mainly in copper. This is consistent with the fact that copper mines operate in the area. A correlation of the values obtained to copper using ICP and PIXE technique was statistically acceptable. Therefore, determination of Cu in river sediment by PIXE allows identification of areas affected by mining activities in river basins of northern Chile.

Trace elements in the scalp hair of patients with alcohol induced psychosis

A number of essential trace elements play a major role in various metabolic pathways and in many diseases like autoimmune, neurological and psychiatric. This study is undertaken with an aim to evaluate the levels of different trace elements in the scalp hair samples of patients suffering from alcohol induced psychosis by particle induced X-ray emission technique (PIXE). It is observed that Fe (p < 0.0005), Cu (p < 0.001) are significantly higher in the hair samples of alcohol induced psychosis patients compared to those in normals while concentrations of Mn (p < 0.005) and Zn (p < 0.0001) are lower. The concentrations of Co and Ni in the hair samples are found to be in consonance with the concentrations in the normals.

A deep view in cultural heritage—confocal micro X-ray spectroscopy for depth resolved elemental analysis

Quantitative X-ray fluorescence (XRF) and particle induced X-ray emission (PIXE) techniques have been developed mostly for the elemental analysis of homogeneous bulk or very simple layered materials. Further on, the microprobe version of both techniques is applied for 2D elemental mapping of surface heterogeneities. At typical XRF/PIXE fixed geometries and exciting energies (15–25 keV and 2–3 MeV, respectively), the analytical signal (characteristic X-ray radiation) emanates from a variable but rather extended depth within the analyzed material, according to the exciting probe energy, set-up geometry, specimen matrix composition and analyte. Consequently, the in-depth resolution offered by XRF and PIXE techniques is rather limited for the characterization of materials with micrometer-scale stratigraphy or 3D heterogeneous structures. This difficulty has been over-passed to some extent in the case of an X-ray or charged particle microprobe by creating the so-called confocal geometry. The field of view of the X-ray spectrometer is spatially restricted by a polycapillary X-ray lens within a sensitive microvolume formed by the two inter-sectioned focal regions. The precise scanning of the analyzed specimen through the confocal microvolume results in depth-sensitive measurements, whereas the additional 2D scanning microprobe possibilities render to element-specific 3D spatial resolution (3D micro-XRF and 3D micro-PIXE). These developments have contributed since 2003 to a variety of fields of applications in environmental, material and life sciences. In contrast to other elemental imaging methods, no size restriction of the objects investigated and the non-destructive character of analysis have been found indispensable for cultural heritage (CH) related applications. The review presents a summary of the experimental set-up developments at synchrotron radiation beamlines, particle accelerators and desktop spectrometers that have driven methodological developments and applications of confocal X-ray microscopy including depth profiling speciation studies by means of confocal X-ray absorption near edge structure (XANES) spectroscopy. The solid mathematical formulation developed for the quantitative in-depth elemental analysis of stratified materials is exemplified and depth profile reconstruction techniques are discussed. Selected CH applications related to the characterization of painted layers from paintings and decorated artifacts (enamels, glasses and ceramics), but also from the study of corrosion and patina layers in glass and metals, respectively, are presented. The analytical capabilities, limitations and future perspectives of the two variants of the confocal micro X-ray spectroscopy, 3D micro-XRF and 3D micro-PIXE, with respect to CH applications are critically assessed and discussed.

Analysis of ancient Indian silver punch-marked coins by external PIXE

Seven silver punch-marked coins were analysed using external particle induced X-ray emission technique. The main group of elements like Ag, Cu, Au, Pb and Fe were estimated along with a number of trace/minor elements such as K, Ca, Ti, V, Cr, Mn, Co, Ni and Rb in the analysed silver coins. Gold was found in all the coins and varied between 0.7% and 6.2% indicating the better economic condition of that civilisation.

On the Quantification of Al Incorporated in SiC Material Using Particle Induced X-Ray Emission Technique

In this work the capability of the proton induced X-ray emission (PIXE) technique to monitor a rapid, non-destructive and accurate quantification of Al on and in Si-based matrix is discussed. Optimization of PIXE acquisition parameters was performed using as reference a thin Al film (2.5 nm) thermally evaporated onto silicon substrate. In order to improve the sensitivity for Al detection and quantitative determination, a systematic study was undertaken using proton ion beam at different energies (from 0.3 to 3 MeV) with a different tilting angle (0°, 60°, and 80°). The limit of detection (LOD) was found to be lower than 0.2 nm. The optimum PIXE conditions (energy, angle) were applied for determining the Al doping concentration in thin (1 µm) 4H-SiC homoepitaxial layer. The Al concentration as determined by PIXE was found to be 3.9x1020 at/cm3 in good agreement with SIMS measurements, and the LOD was estimated to be 6x1018 at/cm3.

2 MeV-PIXE TECHNIQUE FOR COASTAL MATERIAL ANALYSIS

Ion beam analysis (IBA) is a group of PIXE (particle induced X-ray emission) techniques dedicated to the analysis of material for geological sample of coastal sediment samples. Coastal/Beach samples collected from South East Coast of Tamilnadu were analyzed by PIXE technique and obtain the elemental composition of coastal sediments. The PIXE analysis was carried out using 1.7 MV Tandem accelerators with the energy of 2 MeV protons at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, Tamilnadu, India. The data analysis is normally done in an interactive mode of GUPIX analytical software computer code. The identified elements are present in the fingerprint X-ray spectrum in the range of ppm to ppb level. Therefore in this paper, introductory results concerning determination of concentration of chosen elements such as K , P , Ca , Ti , Fe , Cr , Co , Zn , Mn , Ni , Cu , Rb , Sr , As , Zr , Hf , Pb and Hg of coastal sediment samples from the east coast of Tamilnadu, India are presented. The validation of the technique is assessed using standard reference material (SRM) NIST 1646a estuarine sediment and the result shows the good agreement with the certified one. The results were used to assess environmental toxicity of heavy metals and radiation hazard in the study area.

A complimentary tool in the determination of activity concentrations of naturally occurring radionuclides

The determination of activity concentrations of radionuclides requires a reliable gamma spectrometry system, which also depends on the compulsory attainment of secular equilibrium amongst the progenies of the radionuclide of interest. This is often difficult to attain and hence a helium particle induced x-ray emission technique, not requiring the compulsory attainment of secular equilibrium, was used to determine the actual concentrations of the elemental content of tailings from the high background radiation tin mining area, Jos, Nigeria. The activity concentrations of the radionuclides of 40K, 232Th and 238U were also calculated based on their elemental analyses, providing reliable information about the heads of uranium ( 238U) and thorium ( 232Th) series on the study area.

Characterization of Metal and Trace Element Contents of Particulate Matter (PM10) Emitted by Vehicles Running on Brazilian Fuels—Hydrated Ethanol and Gasoline with 22% of Anhydrous Ethanol

Emission of fine particles by mobile sources has been a matter of great concern due to its potential risk both to human health and the environment. Although there is no evidence that one sole component may be responsible for the adverse health outcomes, it is postulated that the metal particle content is one of the most important factors, mainly in relation to oxidative stress. Data concerning the amount and type of metal particles emitted by automotive vehicles using Brazilian fuels are limited. The aim of this study was to identify inhalable particles (PM10) and their trace metal content in two light-duty vehicles where one was fueled with ethanol while the other was fueled with gasoline mixed with 22% of anhydrous ethanol (gasohol); these engines were tested on a chassis dynamometer. The elementary composition of the samples was evaluated by the particle-induced x-ray emission technique. The experiment showed that total emission factors ranged from 2.5 to 11.8 mg/km in the gasohol vehicle, and from 1.2 to 3 mg/km in the ethanol vehicle. The majority of particles emitted were in the fine fraction (PM2.5), in which Al, Si, Ca, and Fe corresponded to 80% of the total weight. PM10 emissions from the ethanol vehicle were about threefold lower than those of gasohol. The elevated amount of fine particulate matter is an aggravating factor, considering that these particles, and consequently associated metals, readily penetrate deeply into the respiratory tract, producing damage to lungs and other tissues.

Elemental characterisation of Cabernet Sauvignon wines using Particle-Induced X-ray Emission (PIXE)

The elemental composition of 2002 Cabernet Sauvignon wines from four different regions of Rio Grande do Sul state (Brazil) was determined using Particle-Induced X-ray Emission (PIXE) technique. In total, wines from 13 different vineyards were studied. Particular attention was given to wines stemming from Vale dos Vinhedos which is one of the most important wine producing regions in Brazil. Typical PIXE spectra consisted of elements with atomic number between 11 and 38 such as P, S, K, Ti, Mn, Fe, Cu, Zn and Rb. Physicochemical variables such as volatile acidity, alcohol, pH and dry extract were also determined for some wines. Variations in the elemental concentrations among wines from Vale dos Vinhedos and from different regions were observed. In general our results are in good agreement with previous measurements of Brazilian wines. With respect to European wines, our results are characterised by relatively low concentrations of Cu and Zn and high concentration of Rb.

Particle-Induced X-ray Emission (PIXE) Analysis of Minor and Trace Elements in Gallstones of Nigerian Patients

Gallstone disease is a major health problem in many parts of the world. In Nigeria, however, only a few cases of gallstone disease are reported. Minor/trace elements are reported to play a significant role in the formation of gallstones. This study was conducted to assess the minor elements in gallstone of Nigerian patients who had cholecystectomy in our institution using particle-induced X-ray emission (PIXE) technique. We also compare the findings with previous reports from outside Nigeria. Fourteen patients who had cholecystectomy for calculous cholecystitis at Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, Nigeria, between March 2006 and July 2008, had the stone retrieved. The stones were analyzed for trace elements at the Center for Energy Research and Developments of the University using PIXE experiments. Certified standard reference material, NIST 1577a (bovine liver), was equally analyzed to confirm the accuracy of the experimental procedure. Computer code GUPIXWIN was used to analyze the data. Fourteen elements, phosphorus, sulfur, chlorine, potassium, calcium, manganese, iron, copper, zinc, bromide, lead, titanium, rubidium, and strontium, were detected in most of the samples. The concentrations of the elements varied in the different samples, ranging from a few parts per million to a few percent. Ca was the major constituent of all samples. The black sand-like samples had very high levels of P, S, K, and Pb, which were different from a previous report. The distribution of trace elements in stones in Nigeria patients is different from previous report outside Nigeria, and this may have some role in the occurrence of gallstones in the black African.

Trace Element Studies on Tinospora cordifolia (Menispermaceae), Ocimum sanctum (Lamiaceae), Moringa oleifera (Moringaceae), and Phyllanthus niruri (Euphorbiaceae) Using PIXE

Traditionally, Tinospora cordifolia (Willd.) Hook. F. & Thomson (Menispermaceae), Ocimum sanctum L. (Lamiaceae), Moringa oleifera Lam. (Moringaceae), and Phyllanthus niruri L. (Euphorbiaceae) are some of the commonly used medicinal plants in India for curing ailments ranging from common cold, skin diseases, and dental infections to major disorders like diabetes, hypertension, jaundice, rheumatism, etc. To understand and correlate their medicinal use, trace element studies on the aqueous extract of these medicinal plants have been carried out using particle-induced X-ray emission technique. A 2-MeV proton beam was used to identify and characterize major and minor elements namely Cl, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, and Sr in them. Results have revealed that these elements are present in varying concentrations in the selected plants. Notable results include very high concentrations of Cl, K, and Ca in all the leaf samples, appreciable levels of Mn in all plants, high Zn content in T. cordifolia, and the aqueous extract of Moringa leaves compared to others and relative higher concentrations of Cr in all the plants.

Biomonitoring study of seasonal anthropogenic influence at the Itamambuca beach (SP, Brazil)

The present work is focused on the study of a seasonal anthropogenic influence on the beach of Itamambuca (Ubatuba, SP, Brazil) carried out using Atherinella brasiliensis as biomonitor. In total 84 fish were caught between July 2004 and February 2005 in different locations at the beach and inside the Itamambuca river. The fish were pooled according to catch and their musculature was analyzed by Particle-Induced X-ray Emission (PIXE) and Rutherford Backscattering (RBS) techniques. While the concentration of light (matrix) elements like C and O were obtained using the RBS technique, major (Na, Mg, P, S, Cl, K and Ca) and trace (Si, Al, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br and Sr) elements were measured by PIXE. The results show that differences were observed for several elemental concentrations of fish tissue between high season (spring-summer) and low season (winter-fall), indicating that increased human activity in the beach during high season may have some impact on the beach ecosystem. The role of the water salinity in the results is also discussed.