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In the present study, we used a silicon drift detector (SDD) for the quantitative analysis of in-air PIXE. First, we examined the basic performances of the detector. We found that the shift of the peak position was less than 0.45 eV, and the energy resolution was 130-136 eV at 5.98 keV. We then used the SDD for a quantitative analysis. Physical parameters, such as the X-ray production cross-sections, values of the transmission of X-rays through absorbers and the detection efficiencies, which are required for quantification, were obtained theoretically and experimentally. We confirmed that many elements, from magnesium to barium, were able to be detected without using any special device. The results of the quantitative analyses of a few standard materials showed good agreement with the certified values. This method was also used to analyze practical samples, including bio-medical samples, and the results were in good agreement with the results obtained with in-vacuum PIXE. [ABSTRACT FROM AUTHOR]

In this paper, methods of quantitative elemental analysis of very small quantity of cultured cells were developed. First of all, an internal-standard method for the solution containing cells whose density is more than 1 × 106 cells/mL was established and then a standard-free method for cultured cells was developed. It was confirmed that the method allows us to quantitatively analyze more than 25 elements in the samples containing only 20,000 cells. Also, the methods for removing cultured cells from a flask were examined in order to improve accuracy and sensitivity of analysis since the use of trypsin and PBS sometimes brings a large amount of sodium, phosphorus and potassium, which have direct effect upon accuracy of analysis based on the standard-free method. It was found that the method of removing cells with a scraper without using trypsin and PBS is the best manner. Also, the effects of using thinner backing materials were examined in order to improve sensitivity of analyses. It is expected that accurate analysis of samples containing nearly two thousand cells is possible on the basis of the standard-free method when using a thinner backing material. [ABSTRACT FROM AUTHOR]

A standard-free method for living plants in in-air PIXE has been developed in order to clarify the mechanism of elemental transportation and movement in farm products. The components of the continuous X-rays originated from air and a backing film can be exactly subtracted using a blank spectrum after normalization by the yields of Ar Kα X-rays. It is found by observing the yield of continuous X-rays with passage of time that water content is continuously decreasing during irradiation with a proton beam in a case of pinched leaves. In contrary, it is kept almost constant during irradiation for the living plants to which water is continuously provided through the roots. Stability of the yield of continuous X-rays is a required condition for a standard-free method, which makes use of the yield of continuous X-rays mainly emitted from water content. It is confirmed that potassium concentration shows no large position dependence on a leaf, and it keeps almost constant during irradiation, which also indicates that regular metabolism is going on. As potassium is always contained in all kinds of plants in large amount, it is designated as an index element. As a result, it is found that the potassium concentration obtained by the present standard-free method shows quite consistent values with those obtained by the internal-standard method. The present method is confirmed to be quite useful for investigating movement of not only toxic elements but also essential elements reflecting metabolism in plants. [ABSTRACT FROM AUTHOR]

The method of quantitative analysis of oil samples in in-air PIXE has been developed on the basis of a standard-free method. The components of the continuous X-rays originated from air and backing film can be exactly subtracted using a blank spectrum after normalization by the yields of Ar K-α X-rays. The method was developed using nine oil samples including standard oils and its accuracy was confirmed by comparing the results with those obtained by the internal-standard method. Validity of the method for practical oil samples was confirmed for various kinds of oils such as engine, machine and cooking oils. It was found that the method is effective for various kinds of oils whatever elements we designate as an index element. [ABSTRACT FROM AUTHOR]

The standard-free method developed by ourselves 13 years ago has been widely applied to quantitative analyses of hairs such as head hair taken from human and body hair taken from companion and domestic animals. In the present work, the standard-free method for feather and down samples taken from wild birds such as swan, waxwing, osprey, heron and crow is developed. It is found that the standard-free method developed for human hairs can be successfully applied to feather samples without essential modification since the main constituents of feather are almost the same as those for human and animal hairs and, consequently, the shape of continuous X-rays is also the same. Accuracy and sensitivity of the present method were examined by comparing the results with those obtained by an internal-standard method combined with a chemical-ashing method. The method allows us to quantitatively analyze untreated feather samples of very small quantities and to prepare the target without complicated preparation technique. It is expected that the method will become a powerful tool for the studies not only on the mode of life of wild birds but also on environmental contamination by toxic elements. [ABSTRACT FROM AUTHOR]

A standard-free method for small lymph node and spleen samples taken from rats, and lymph node, esophagus, colon etc. taken from real patients has been developed in order to take measure to meet increasing demands for quantitative analyses of small amount of organs. It becomes possible to quantitatively analyze organ samples of less than 1 mg collected from small experimental animals and also from patients by biopsy, and accuracy and sensitivity of the method were examined by comparing the results with those obtained by a powdered-internal-standard method and a chemical-ashing method. It is found that the method is quite effective for estimating therapeutic effect of CDDP (Cisplatin) since it allows us to quantitatively evaluate uptake of CDDP into organs by analyzing small quantity of samples taken from actual patients by biopsy. It is expected that the method will become a powerful tool for studies not only in fundamental and clinical medicines but also on practical diagnosis and treatment. [ABSTRACT FROM AUTHOR]

A simultaneous measuring system of two different targets by in-vacuum and in-air PIXE has been developed in order to improve efficiency of analyses in the limited machine time. The proton beam passes through a thin target in vacuum and it allows us to perform in-vacuum PIXE, and the beam is further transported to the in-air PIXE system for analyzing another target. The beam intensity for in-air PIXE while performing in-vacuum PIXE is 1.5 nA, which is almost sufficient. The effect of slight changes in the beam transport parameters on the background X-rays for both in-vacuum and in-air PIXE has been found to be negligible. As a result, it is confirmed that accuracy and sensitivity of analysis for many kinds of sample, such as various samples in earth, environmental sciences and in bio-medicine, are almost unchanged for the both systems, and a four-detector-simultaneous measuring system has been completed. It is expected that the system will work miracle for solving the problem of deficient machine time in our laboratory. [ABSTRACT FROM AUTHOR]

Standard-free method for untreated hair samples in in-air PIXE has been developed. It is confirmed that the method gives us good sensitivity and accuracy within several minutes' measurement if more than twenty hairs are attached onto the target. Even in the case where the number of hairs is less than eight, which is regular for usual in-vacuum PIXE, 10-15 minutes measurement is found to be sufficient to achieve almost satisfactory sensitivity and accuracy for elements from Cl to Pb. As the present method allows us to carry out analyses without labor in target preparation, it is expected to be quite helpful in the studies on human exposure to toxic elements. Its availability will more and more increase when the method is combined with the method of simultaneous measurement of in-vacuum and in-air PIXE we have just developed. [ABSTRACT FROM AUTHOR]

A physical method of quantitative analysis for in-air PIXE has been established. Among the three parameters required for performing physical analysis, X-ray production cross sections were recalculated by using the effective energy of the proton beam after losing its energy through a Kapton foil and in air. Detection efficiencies of the Si(Li) detector have been determined according to our method established for in vacuum system, where effects of absorption of X-rays in air are incorporated into the detection efficiencies. As a result, it is confirmed that the present method gives us accurate results in the analyses of standard samples as well as actual samples such as soil and ash. It becomes possible to perform quantitative analysis of various samples by optimizing the measuring conditions depending on the samples. [ABSTRACT FROM AUTHOR]

We recently developed and reported a three-detector measuring system making use of a pure-Ge detector combined with two Si(Li) detectors. The efficiency curve of the pure-Ge detector was determined as relative efficiencies to those of the existing Si(Li) detectors and accuracy of it was continued by analyzing a few samples whose elemental concentrations were known it was found that detection of fluorine becomes possible by analysing prompt γ-rays and the detection limit was found in be less than 0.1 ppm for water samples. In this work, a method of quantitative analysis of fluorine has been established in order to investigate environmental contamination by fluorine. This method is based on the fact that both characteristic x-rays from many elements and 110 keV prompt γ-rays from fluorine can be detected in the same spectrum. The present method is applied to analyses of a few environmental samples such as tealeaves, feed for domestic animals and human bone. The results are consistent with those obtained by other methods and it is found that the present method is quite useful and convenient for investigation studies on regional pollution by fluorine. [ABSTRACT FROM AUTHOR]