Narrow Results

We studied the effects of aluminum on macro- and microelement concentrations in white roots of Chamaecyparis obtuse and Quercus serrata Thunb. through analysis by Particle Induced X-ray Emission (PIXE). One-year-old seedlings were exposed to various concentrations of Al for nine weeks. In both species, the Al and P concentrations increased as the Al concentration in the nutrient solution increased, but the concentrations of the divalent cations Mg, Zn, and Mn decreased in both species.

In order to confirm the accuracy of direct analysis of filter samples containing atmospheric aerosol particles collected on a polycarbonate membrane filter by PIXE, we carried out PIXE analysis on a polycarbonate membrane filter (Nuclepore^®, pore size: 0.8 μm) on which was collected National Institute of Standards and Technology (NIST, USA) urban particulate matter (SRM 1648). We also investigated whether a polycarbonate membrane filter would possibly bias elemental quality determined by PIXE analysis. We found that the polycarbonate membrane filter did not bias values determined by PIXE. In the case of filter sample A in which the powder sample (urban particulate matter mixed with palladium-carbon powder (5% Pd)) was collected under dry conditions, elemental quantitative values were 80–110% relative to NIST certified and non-certified values except for Mn and Fe. On the other hand, in the case of filter sample B in which the powder sample was collected under wet conditions, elemental quantitative values were 70–110% relative to NIST certified and non-certified values except for Cl and Zn. Determined values for Mn and Fe in the case of filter sample A and Cl and Zn in the case of filter sample B were clearly lower than NIST certified and/or non-certified values, but this is believed to be attributable to the sampling procedure rather than a problem associated with PIXE analysis. Direct analysis of a filter sample containing aerosol particles by PIXE provided sufficient elemental quantity accuracy.

We attempted in-air-PIXE analysis of SPM using spot samples on a filter-tape mounted in an automated beta-ray absorption mass monitor. Al, Si, S, Fe and Zn, etc., which are of interest for identifying the behavior and characteristics of SPM, were detected on the SPM spot samples on a glass-fiber filter-tape, but the peaks of these elements were nearly identical to those of blank glass-fiber filter-tape. As such, it was difficult to detect elements present in SPM from the X-ray spectra of the spot samples. On the other hand, in the case of a PTFE membrane filter-tape, the S peak was distinct and the Fe peak was also clear, and peaks for elements Al, Mn and Zn, etc., were also confirmed. Consequently, if a method for determining quantity is established, direct multi-elemental analysis by in-air-PIXE of high time-resolution SPM spot samples collected on a PTFE membrane filter-tape mounted in a SPM monitor will be possible.

In order to confirm accuracy of the direct analysis of filter samples containing atmospheric aerosol particles collected on a polycarbonate membrane filter by PIXE, we carried out PIXE analysis on a National Institute of Standards and Technology (NIST, USA) air particulate on filter media (SRM 2783). For 16 elements with NIST certified values determined by PIXE analysis — Na, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb — quantitative values were 80–110% relative to NIST certified values except for Na, Al, Si and Ni. Quantitative values of Na, Al and Si were 140–170% relative to NIST certified values, which were all high, and Ni was 64%. One possible reason why the quantitative values of Na, Al and Si were higher than the NIST certified values could be the difference in the X-ray spectrum analysis method used.

In order to obtain high time-resolution, i.e., chemical data of atmospheric particulate matter (PM) at one-hour intervals, we carried out direct analysis of suspended particulate matter (SPM) on hourly spot samples on a new type of PTFE ultra-membrane filter-tape mounted in an automated beta-ray absorption mass monitor by conventional PIXE. Analysis of hourly SPM spot samples revealed 20 elements (Na, Mg, Al, Si, S, Cl, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Sr and Pb) in total. Therefore, we are convinced that the chemical information that is obtained from high time-resolution PM spot samples on a PTFE membrane filter-tape mounted in an automated beta-ray absorption mass monitor will lead to new developments in PM research. Furthermore, elemental data obtained by the high time-resolution along with data for ionic species compositions, and SO₂, NO_X and other gaseous air pollutants at the same level, will make possible the analysis of detailed air pollution phenomenon.

Eighty-nine wild birds were found dead in Ogata Village in northern Japan in March 2006. Eighty-eight of the birds were rooks (Corvus Frugilegus Pastinator), which are migratory birds. Since the use of rodenticide (thallium sulfide and zinc phosphide) in the area around where the birds had been found was revealed by a survey, etiological and pathological examinations including elemental analysis by means of particle induced X-ray emission (PIXE) were conducted. Elemental analysis showed high concentrations (56–365 dry-μg/g) of thallium in the lungs, gastric contents, intestines, livers and kidneys. Histopathological examination revealed vacuolar degeneration of hepatic cells and granular and/or hyaline droplet degeneration of renal tubular epithelia. The results suggest that the mass deaths were caused by thallium poisoning.

In order to confirm the availability of an in-air Helium ion induced X-ray emission method for multi-elemental analysis of polytetrafluoroetylene (PTFE) filter sample containing atmospheric particles, NIST urban particulate matter (SRM 1648) collected on PTFE filter using a special small chamber was analyzed by an in-air PIXE method with Helium ions and a proton beam. In addition, we analyzed 10 elements, mixing a standard solution with different concentrations to confirm detection sensitivity of characteristic X-ray peaks. As a result, it is suggested that 1) elements that are lighter than Zn and Pb can be satisfactorily measured using the in-air Helium ion induced X-ray emission method if the amount contained in the filter sample is at least 0.1 mg/L, i.e., 15 ng/cm², 2) the in-air Helium ion induced X-ray emission method is useful as a method for quantitatively analyzing the light elements such as Mg, Al, Si, S and Cl that are important for identifying the behavior and characteristics of atmospheric particles from the PTFE filter sample containing atmospheric particles, and 3) in the case of the PTFE filter sample containing atmospheric particles, it is possible to measure elements from Mg to Pb by means of analysis using Helium ions and protons.

We developed an original preparation method for honey samples (samples in paste-like state) specifically designed for PIXE analysis. The results of PIXE analysis of thin targets prepared by adding a standard containing nine elements to honey samples demonstrated that the preparation method bestowed sufficient accuracy on quantitative values. PIXE analysis of 13 kinds of honey was performed, and eight mineral components (Si, P, S, K, Ca, Mn, Cu and Zn) were detected in all honey samples. The principal mineral components were K and Ca, and the quantitative value for K accounted for the majority of the total value for mineral components. K content in honey varies greatly depending on the plant source. Chestnuts had the highest K content. In fact, it was 2–3 times that of Manuka, which is known as a high quality honey. K content of false-acacia, which is produced in the greatest abundance, was 1/20 that of chestnuts.

We originally developed a preparation method for samples of automobile engine lubricating oil (liquid sample) specifically designed for in-air particle induced X-ray emission (PIXE) analysis with Helium ions. In the developed preparation method, target samples were fixed by making the oil sample sandwiches with 1% collodion solution based ethanol. With this analytical method, elements such as Al, Si, P, S, Cl, Ca and Zn can be detected from the oil samples, while Si, P, S, Ca and Zn were the elemental components of the oil additives.

Beech (Fagus crenata) leaves were collected at three sites in and near the Shirakami-Sanchi World Heritage Area (a mountainous region) during the plant growing season of year 1999. The composition and concentration of the elements were determined by the method of Particle Induced X-ray Emission (PIXE). Thirty one elements were determined in total. Na, Mg, Si, P, S, Cl, K, Ca, Mn and Fe were found to be the most important elements in all sites. The concentrations of Na, Si and Cl in leaves were found to be increased with the growth of leaves, while those of P, S and K were to be decreased. The concentrations of other major elements did not change with respect to leaf phenology. Those analysis of the elements in the beech leaves suggested that 1) Na, Si and Cl are the key elements for judging the air pollution phenomenon, 2) P, S, K, Ca, Mn, Fe, Cu, Zn and Rb may play an important role for the metabolism of plants.

The segregation and disposal of chromated copper arsenate (CCA)-treated wood waste when recycling building waste materials is a serious issue. We examined the contents of CCA preserved cedar timber by PIXE analysis. CCA preserved timber contained large amounts of these metals both on the surface and core of the wood. The ratio of chromium, copper and arsenic contained on the surface was 1:2:1, and in contrast, the ratio in the core was 1:1:2. In other words, the arsenic content was highest in the core. Moreover, the chemical form of arsenic in both parts of the wood was only inorganic arsenic; the same form of arsenic in preservative components known as carcinogenic substances. These findings mean that the complete separation of waste CCA preserved timber from construction and demolition wood is needed.

Fresh surface snow samples were collected at the summit or near the summit (700 - 1500 m altitude) of five mountains in Akita Pref., Japan. The elemental composition and particle shape of insoluble material in these snow samples was determined and/or observed by Particle Induced X-ray Emission (PIXE), a Scanning Electron Microscope (SEM) combined with Energy Dispersive X-ray (EDX) analysis. 21 kinds of elements for each mountain snow sample were determined by PIXE. Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti and Fe were the major components in each of the mountain snow samples, and those in relative abundance were almost the same in each case. With the aid of SEM and EDX analysis, silicon-rich small sphere (spherule) particles and aggregates of car exhaust particles were observed in every mountain snow sample. These results are represented as insoluble components of clouds and provide important knowledge for the source and mechanism of snowfall and rainfall at the ground level.

Particulate matter (PM-3.9 and PM-15.8) samples were collected in the three zones at the Northeast, Southwest and Southeast suburbs of Mexico City, from July to August 1998, for one week for each sampling site. The concentrations of several elements in the PM-3.9 and PM-15.8 samples were determined by Particle Induced X-ray Emission (PIXE). In the PM-3.9 samples, 21 elements were determined for each zone, and Na, Mg, Al, Si, S, K, Ca, Ti, Fe, Cu, Zn and Pb are found to be the major elemental components. On the other hand, 22 elements including P were determined on the PM-15.8 samples, and the dominant elements were the same as in the PM-3.9. Factor analysis is applied to the 28 variables (14 elements for each PM-3.9 and PM-15.8 groups) and for 21 samples (seven days for three zones) in order to identify possible sources of the particles. The result of factor analysis allows to identify five major sources, being soil the major contributor.