Proton Induced X-ray Emission Method Research Articles

Using the PIXE method to evaluate the characteristics of aerosols in Kumamoto City, Southwestern Japan, from March 2004 to March 2007

Recently, atmospheric particles, including Asian dust, have attracted considerable attention because of their potential effects on the environment and human health. From March to May, a huge volume of Asian dust is whipped up over China and carried to Japan by the westerly winds. In this study, we analyzed the elemental compositions of 72 aerosol samples collected biweekly in Kumamoto City from March 2004 to March 2007, to investigate the characteristics of Asian dust. The mass concentrations of the aerosol in Asian dust events were 1.5 times higher than non-Asian dust events. The concentrations of elements were determined by the Proton Induced X-ray Emission (PIXE) method. Concentrations of Si, Al, Fe, Ca, Ti, Mg and K in Asian dust events were 2.3, 2.0, 2.0, 1.6, 1.6, 1.5 and 1.4 times higher than those in non-Asian dust events, respectively. These elements are considered indicators of a soil-derived fraction. The concentrations of the soil-derived fraction were calculated, assuming that the Al concentration in the soils is 7%. The predicted mean concentration of the soil-derived fraction in Asian dust events (16.92 μg·m−3) was twice that in non-Asian dust events (8.39 μg·m−3). Moreover, in Asian dust events, the soil-derived fraction was the main component in aerosols and accounted for 43% of the total aerosol mass.

Honey Bee tissues as a biomarker for Environmental pollution with heavy metals.

The purpose of this study is to verify the importance of the body surface and tissues of foraginghoney bee Apis mellifera as bioaccumulator of heavy metals that can therefore, be included inbiomonitoring programmes of heavy metals in terrestrial ecosystems. The presence of fiverepresentative heavy metals (copper, zinc, cadmium, lead and iron) was investigated in honeybee tissues (mid gut, hind gut and fat body), body surface and wings using proton induced X-rayemission method. X-ray spectrums of mid gut and fat body of forager bees demonstrated smallpeaks for Cd, Pb, Fe and Ni compared to the control. Moreover, slightly larger peaks for Cu andZn were noticed in the X-ray spectrums of whole honey bee mid gut, hind gut and fat body thanthose of the control. Forager honey bee body surface showed small peaks for Cu and Pbcompared to the control. Similarly, small peaks for Cd, Pb and Ni were noticed in the X-rayspectrums of wings and hind gut of the forager honey bee compared to control.

Characterization of size-resolved aerosol components using proton induced X-ray emission, inductively coupled plasma optical emission spectrometry and ion chromatography

Size-resolved aerosol monitoring for PM10, PM2.5, and PM1.0 was performed to qualify and quantify the elements and ions by using proton induced X-ray emission (PIXE), inductively coupled plasma optical emission spectrometry (ICP-OES), and ion chromatography (IC) analysis. Time-resolved aerosol samplings based on 2-hour and 14-hour intervals were carried out during daytime and nighttime, respectively. Physical and chemical properties of size-resolved aerosols were investigated to characterize air quality in the national park area of Gyeongju, Korea. The PIXE and ICPOES methods made elemental mass of Al, Si, S, K, Ca, Ti, Cr, Fe, Sr, and Pb. And ions of Na+, NH4+, Ca2+, Cl−, NO3−, and SO42− were analyzed by the IC method. The mass concentrations of Si, S, Ti, and Pb determined by PIXE showed relatively good correlation with those determined by ICP-OES. But Fe and Sr had worse correlations with an average R2 of 0.4703 and 0.4825, respectively. The PIXE method was a good alternative to measure chemical species of Al, Si, S, K, Ca, Ti, Cr, and Pb for size-resolved aerosols except Fe and Sr in this study. The average relative errors of sizeresolved elements for 2-hour and 14-hour interval collections were 10.1±5.7% (0.1–28.3%) and 9.9±7.7% (1.3–38.4%). Ammonium sulfates (AS), mineral dust (MD), and sea salt (SS) aerosols were reconstructed from the elements determined by PIXE and ICP-OES and ions obtained by IC. The mass concentration of MD was calculated with crustal elements of Al, Si, Ca, Ti, and Fe, which are associated with soil erosion. The average relative error of MD was the lowest value of 0.8% in the PM10 regime and the highest value of 10.0% in the PM1.0 regime. The average relative errors of AS for PM10, PM2.5, and PM1.0 determined by PIXE, ICP-OES, and IC showed relatively lower values of 0.8–5.7%, 1.7–5.9%, and 3.3–8.3%, respectively. The average mass concentrations of AS, MD, and SS of PM10, PM2.5, and PM1.0 except submicron SS determined by PIXE were comparable to those determined by ICP-OES and IC within the acceptable relative errors.

Influence of Vanadium–organic Ligands Treatment on Selected Metal Levels in Kidneys of STZ Rats

The objective of the study was to investigate the effects of five organic vanadium complexes supplement and a small dose of insulin injection on V, Fe, Cu, Zn, Mn, Ca, and K level in the streptozotocin diabetic rat’s kidney during a 5-week treatment with the tested complexes. In all groups of animals, metal level in the lyophilized kidney organs was investigated by means of the proton induced X-ray emission method. Tissue vanadium level was naturally higher in vanadium-treated rats. The maximum level of vanadium was observed in the kidney ( {x_{text mean}} =16.6 upmu mathrm{g}/left. mathrm{g} right) . The influence of vanadium administration on other metal level in rat’s tissue was also investigated. Spectacular influence of vanadium action was observed on copper and zinc level in examined tissue.

Chemical speciation of chlorine in atmospheric aerosol samples by high-resolution proton induced X-ray emission spectroscopy

Chlorine is a main elemental component of atmospheric particulate matter (APM). The knowledge of the chemical form of chlorine is of primary importance for source apportionment and for estimation of health effects of APM. In this work the applicability of high-resolution wavelength dispersive proton induced X-ray emission (PIXE) spectroscopy for chemical speciation of chlorine in fine fraction atmospheric aerosols is studied. A Johansson-type crystal spectrometer with energy resolution below the natural linewidth of Cl K lines was used to record the high-resolution Kα and Kβ proton induced spectra of several reference Cl compounds and two atmospheric aerosol samples, which were collected for conventional PIXE analysis. The Kα spectra which refers to the oxidation state, showed very minor differences due to the high electronegativity of Cl. However, the Kβ spectra exhibited pronounced chemical effects which were significant enough to perform chemical speciation. The major chlorine component in two fine fraction aerosol samples collected during a 2010 winter campaign in Budapest was clearly identified as NaCl by comparing the high-resolution Cl Kβ spectra from the aerosol samples with the corresponding reference spectra. This work demonstrates the feasibility of high-resolution PIXE method for chemical speciation of Cl in aerosols.

Characterization of PM10 atmospheric aerosol at urban and urban background sites in Fuzhou city, China

PM(10) aerosol samples were simultaneously collected at two urban and one urban background sites in Fuzhou city during two sampling campaigns in summer and winter. PM(10) mass concentrations and chemical compositions were determined. Water-soluble inorganic ions (Cl(-), NO(3)(-), SO(4)(2-), NH(4)(+), K(+), Na(+), Ca(2+), and Mg(2+)), carbonaceous species (elemental carbon and organic carbon), and elements (Al, Si, Mg, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, and Pb) were detected using ion chromatography, thermal/optical reflectance, and proton-induced X-ray emission methods, respectively. PM(10) mass concentrations, as well as most of the chemical components, were significantly increased from urban background to urban sites, which were due to enhanced anthropogenic activities in urban areas. Elements, carbonaceous species, and most of the ions were more uniformly distributed at different types of sites in winter, whereas secondary ion SO(4)(2-), NO(3)(-), and NH(4)(+) showed more evident urban-background contrast in this season. The chemical mass closure indicated that mineral dust, organic matters, and sulfate were the most abundant components in PM(10). The sum of individually measured components accounted for 86.9-97.7% of the total measured PM(10) concentration, and the discrepancy was larger in urban area than in urban background area. According to the principal component analysis-multivariate linear regression model, mineral dust, secondary inorganic ions, sea salt, and motor vehicle were mainly responsible for the PM(10) particles in Fuzhou atmosphere, and contributed 19.9%, 53.3%, 21.3%, and 5.5% of PM(10), respectively.

Semi-Continuous Aerosol Measurement for Visibility Variation Using an External Beam PIXE Method

This study introduces the application of a semi-continuous monitoring and analytic technique to examine the elemental composition for a visibility-impairing aerosol. Semi-continuous measurements of the chemical composition for visibility-impairing aerosol were made during the spring period of 19 30 May 2007 in the urban area of Seoul, Korea. These included measurements of the aerosol elemental composition by a proton induced X-ray emission (PIXE) method, of the aerosol ionic composition by ion chromatography (IC) method and of the aerosol carbonaceous composition by a thermal optical transmittance (TOT) method. Light extinction, scattering and absorption coe cients were measured simultaneously with a transmissometer, a nephelometer and an aethalometer, respectively. The average light extinction coe cient and visual range were measured to be 343 186 Mm 1 and 11.8 4.2 km, respectively, during the intensive monitoring period. The average mass concentrations of PM1:0, PM2:5 and PM10 were measured to be 24.0 13.4, 44.6 30.6 and 77.0 56.1 g m 3 and the correlation coe cient r2 of submicron and ne particles to bext were calculated to be relatively higher values of 0.7835 and 0.7824, respectively. However, the value of r2 for coarse particles was a low value of 0.1261. The results revealed that visibility impairment in the urban atmosphere of Seoul was a ected by ne particles, including submicron particles, rather than coarse particles. On a clear day and a hazy day, the mass concentration of mineral dust was not sensitive to variations in bext. On an Asian dust event day, visibility degradation was dominantly caused by increases in the SO2 4 and the NO 3 components between 12:00 and 14:00, during which time they combined with a large loading of mineral dust caused severely reduced visibility. The ability to observe rapid changes in the aerosol composition using semi-continuous aerosol measurements and the PIXE method was helpful in understanding the diurnal variation of visibility.

The influence of matrix composition and ink layer thickness on iron gall ink determination by the PIXE method

The elemental composition of iron gall inks in historical documents can be effectively studied using the non-destructive proton induced X-ray emission (PIXE) method. The in-air proton beam experimental set-up installed at the Microanalytical Centre of the Jožef Stefan Institute was used for this purpose. The aim of the present investigation was to model and evaluate the uncertainties in the analysis due to the incompletely known matrix composition and iron gall ink layer thickness. Estimation of these uncertainties helped in quantifying the accuracy of multi-elemental PIXE analysis of historical documents.

Investigation of sulfate and nitrate formation on mineral dust particles by receptor modeling

The formation of sulfate and nitrate by heterogeneous reactions of gaseous precursors on mineral dust particles was investigated using positive matrix factorization (PMF) of coarse PM 10 (particulate diameters from 2.2 to 10 μm) collected at urban (Hanoi) and rural (Lucnam) sites in northern Vietnam. Air samples were analyzed for ionic and elemental components using ion chromatography and proton induced X-ray emission methods. PMF revealed six similar sources/types of coarse PM 10 at the two sites, namely soil dust containing nitrate and sulfate, coal fly ash from distant and local sources, soil dust containing organic matter and ammonium sulfate and marine aerosol. Traffic (road) dust was found only at the urban site. From the PMF factor models, the yields of NO 3 - , SO 4 2 - and NH 4 + can be estimated and their possible chemical forms in different particulate types can be suggested. The yields of nitrate and sulfate formation on mineral dust particles increase with the [Ca]/[Si] ratio, which is greater in soil dust than in coal fly ash. Nitrate is bound to Ca-richest soil dust particles. Ammonium was found in dust particles containing soil organic matter, which also hold the largest amount of sulfate. The comparison of urban and rural receptor models provided synergy for the source identification and insights into the properties of mineral dust particles relevant to their interactions with acidic gases in ambient air.

Application of the PIXE method to organic objects

The contribution presents the application of proton induced X-ray emission (PIXE), as a non-destructive analytical method, to the identification and study of historic paper, parchment and textile objects. The results show the possibilities for identification of inks, pigments, dyes, surface layers and inorganic impurities in historic objects made of organic materials. The measurement of elemental concentrations in these materials provides a sound basis for investigation of their composition and of degradation processes. PIXE has been found useful in evaluating the viability of a range of potential conservation treatments by measuring the elemental changes before and after the process has been carried out. Like any other form of analysis, the PIXE method has its limitations, but its great strength is in its non-destructiveness, high sensitivity and accuracy in determining composition and concentration distribution over a wide range of chemical elements. For objects made of complex organic materials the information obtained should be interpreted in combination with other analytical methods.

Studies of crystal orientation and calcium distribution in trabecular bone

These studies were focused on the relation between the orientation of crystallites, calcium concentrations and the stress distributions within human vertebral bodies. The elemental composition was measured using the proton induced X-ray emission method in combination with a proton microprobe (micro-PIXE) while the orientation of the hydroxyapatite crystals was extracted from the X-ray diffraction spectra acquired during the synchrotron microprobe irradiation (micro-XRD). To calculate the distribution of stresses the finite element (FE) method was applied. The distributions of Ca concentrations indicate that the irradiated samples differ slightly in the degree of mineralization. The micro-XRD data confirmed that c-axes of the hydroxyapatite crystallites are preferentially oriented ((40–80)% of the crystals are textured). The comparison of the micro-XRD data and the results of the FE calculations proved the hypothesis that the preferential orientation of crystals reflects the mechanical loading of the structure.

Atmospheric Concentrations of PM2.5 Trace Elements in the Seoul Urban Area of South Korea

Fine particles (PM2.5) were collected during all four seasons, from April 2001 to February 2002, in Seoul, South Korea, using an annular denuder system. Elemental compositions of ambient PM2.5 were analyzed using the proton-induced X-ray emission method. The greatest contributors (≥2%) to the PM2.5 mass were sulfur (S), silicon (Si), chlorine (Cl), aluminum (Al), and iron (Fe) in the spring; S in the summer; and S and Cl in the fall. S, Cl, and Si were the major elements in the winter. S was the most abundant species among the elements, ranging from 5.3 to 7.9%, followed by Si and Cl. From analysis of variance, PM2.5 mass, Al, Si, potassium, calcium, and Fe showed significant seasonal differences during the four seasons (p < 0.001). Enrichment factor (EF) analysis was carried out to identify the sources affecting the aerosol in the Seoul area. On the basis of the mean EF values, elemental S, copper, zinc, and lead may be emitted from anthropogenic sources (EF > 50). Elemental Al, Si, titanium, and Fe may be emitted from crustal sources (EF < 3). Additionally, a correlation analysis was carried out for source identification. The results of the correlation analysis were confirmed by the results of the EF analysis.

Distribution of Chemical Elements of Iron-Gall Ink Writing Studied by the PIXE Method

The chemical element profiles of iron-gall ink writing before and after water treatment and deacidification were determined. A 17th century manuscript of rag paper was used in the study. The chemical elemental analysis was performed non-destructively by the Proton Induced X-ray Emission (PIXE) method. The concentration profiles of 15 elements ranging from Na to Pb were measured with the precision of 0.3 mm. Quantitative composition of ink and paper was determined and the elemental concentration changes due to the aqueous treatments were traced by PIXE. It is considered that the method can be developed and could help conservators in a decision making process.

Relationship of blood trace elements to liver damage, nutritional status, and oxidative stress in chronic nonalcoholic liver disease.

Trace elements are involved in chronic liver diseases because these elements may have a direct hepatic toxicity or may be decreased as a consequence of the impaired liver function, particularly in patients with alcoholic cirrhosis and/or malnutrition. In this study, we determined plasma and erythrocytes trace elements in 50 inpatients with nonalcoholic chronic liver disease (11 with biopsy-proven chronic hepatitis, 39 with cirrhosis [16 in stage A according to Child-Pugh criteria, 23 Child B+C]), and in a control group of 10 healthy subjects by the proton induced x-ray emission method. The relationship between trace element concentration and the extent of liver damage, the nutritional status (by anthropometric evaluations), and various blood markers of oxidative stress--reduced glutathione, total lipoperoxides and malonyldialdehyde--was investigated. We found that cirrhotics had a significant decrease of Fe, Zn, Se, and GSH levels in the plasma and of GSH and Se in the erythrocytes with respect to the control and chronic hepatitis groups. GSH levels were related to the degree of liver damage; a significant direct correlation was observed among Se, Zn, and GSH plasma values and between GSH and Se in the erythrocytes. The trace element decrease was, on the contrary, independent of the degree of liver function impairment and only partially affected by the nutritional status. Data indicate that liver cirrhosis, even if not alcohol related, induces a decrease of Se and Zn and that, in these patients, an oxidative stress is present, as documented by the significant correlation between Se and GSH. The plasma Br level was higher in cirrhotics with respect to the control and chronic hepatitis groups.

Determination of vanadium in animal tissues by PIXE and AAS

Proton induced X-ray emission (PIXE) and atomic absorption spectroscopy (AAS) were used for vanadium determination in animal tissues. The vanadium concentration levels were determined in blood, kidneys and livers taken from rats. Two groups of the animals were treated with different diets. The diet for the first group was supplemented with vanadium compounds while the diet for the second one was assumed to be a “normal” diet. The second group was treated as control. In order to achieve the best minimum detectable limit (MDL)1 the samples were subject to a special sample preparation procedure. Blood and kidneys were mineralized with an APDC compound. The mineralization process was performed according to the procedure described previously.2 The application of PIXE3 is very useful for different types of samples. PIXE measurements were performed with a proton beam at the Institute of Nuclear Physics in Cracow, Poland while the AAS measurements were done at the Institute of Molecular Biology, Jagiellonian University, Poland. The concentration levels of vanadium in blood and kidneys are compared and discussed. There were no significant statistical differences between results of vanadium concentration levels determined by the abovementioned techniques. The PIXE technique had the advantage over the AAS technique of giving a broad spectrum of trace elements analyzed in a single measurement. Therefore with the help of sample preparation procedure the application of the PIXE method seems to be suitable for such analyzes.

Composition of urban and rural aerosol samples collected in the Great Hungarian Plain

Urban and rural atmospheric aerosol samples have been collected simultaneously during 1997 in the Great Hungarian Plain. The elemental composition of the coarse and fine mode aerosol have been determined by the Proton-Induced X-ray Emission method. From the observed elemental concentrations, seasonal variations and variations with the wind sector distributions were found for separate elements. Principal component analyses gave four factors in urban aerosol, and three factors in the rural one. The order of the factors in the coarse mode aerosol is different from the order, found in the fine mode.

COMPOSITION AND SOURCES OF URBAN AND RURAL ATMOSPHERIC AEROSOL IN EASTERN HUNGARY

In an eastern Hungarian region urban and rural aerosol samples have been collected regularly over several years. Concentrations have been determined for 19 elements by the protoninduced X-ray emission method. The examined concentrations have been compared with other data representative for source areas influencing Hungarian atmosphere as well as for typical conditions in Western Europe. Seasonal variations, correlations with the amount of precipitation and wind sector distributions were observed for separate elements. Absolute principal component analysis revealed four typical factors contributing to the aerosol burden. Trajectory sector analysis has been used for studying the influence of long-range transport from the heavily industrialized “Black triangle” area in Central/Eastern Europe on the one hand and Saharan area on the other. Our data offer further basis to investigate the existence and nature of differences between air qualities in Western and Eastern Europe caused by structural and technological differences in the energy sector and industry of the regions mentioned.

Tropospheric Gases and Aerosols in Northeast Greenland

Measurements of atmospheric pollution have taken place in northeast Greenland since 1990. Weekly samples have been collected for analysis of sulfur dioxide, sulfate in particles, and total gaseous and particulate phases of reduced and of oxidized nitrogen. In addition concentrations of a considerable number of elements in aerosols have been determined by the proton induced X-ray emission method. The results show that although the levels of all pollutants are generally very low there are large and recurrent seasonal variations where concentrations rise to considerable heights, similar to observations at other high Arctic sites. The periods of high concentrations fall in different seasons, primarily in winter, depending on the type of pollution and the source type responsible. Winter concentrations of sulfur have decreased in the last few years. A receptor model is used for identifying the natural and anthropogenic source types most important at station Nord, for apportioning concentrations to these sources and for determination of the seasonal variation of the source strengths. The recurrent influence of remote sources on the air quality in the high Arctic indicates that large-scale meteorological mechanisms, similar from year to year, are responsible. For the sulfur compounds this hypothethis is confirmed by model calculations. The results obtained with an Eulerian hemispheric model show that a significant atmospheric pollution transport from very distant sources in industrial areas in Europe and Russia takes place in winter. This transport often occurs in episodes. The deposition is, however, not very high.

PIXE ANALYSIS OF CHINESE CHICKEN-BLOOD STONE

This paper reports the chemical compositions of chicken-blood stone Ji Xue Shi measured by Proton Induced X-ray Emission (PIXE). The experimental result show that for the red portion of chicken-blood stone, the concentration of Hg is as high as 20 wt%, and the concentration of S can be above 10 wt%. For the non-red portion the main chemical compositions are Al 2 O 3 and SiO 2. The obtained chemical compositions are close to those of kaolinite for Balin chicken-blood stone, and of pyrophyllite for Changhua chicken-blood stone, respectively. So far many Changhua chicken-blood stones and Balin chicken-blood stones were found in China, the PIXE method can be used to explore the provenance of available chicken-blood stones.

Non-destructive analysis and appraisal of paper-like objects

This paper reports the experimental results of external proton beam radiation damage on paper. The damage effect was observed by the tensile strength degradation and the change of the structure measured by XRD. The limit doses of 2.5–3.5 MeV proton beam for some kinds of paper are given. This paper also reports the experimental results of the identification of some Chinese stamps of different editions. The proton induced X-ray emission (PIXE) method has also been used to identify forged notes, including false Renminbi and US Dollar found in China. The PIXE spectrum measured from the forged notes shows that the elemental composition is different from that of genuine ones. The PIXE spectra from the forged notes made by different counterfeiters are different from each other. So the PIXE method is a helpful tool to unveil the provenance of the forged notes.