Authors:S. Kataoka, Y. Higaki, Y. Tarumi, S. Tazawa, S. Imai, and T. Nozaki
In order to develop a highly reliable method of routine charged particle activation analysis on a commercial basis by request of an outside company, (1) a new target holder was developed for brittle or low melting-point samples, (2) some modifications and improvements were introduced in the chemical separation, and (3) the reliability of the results was further examined. Oxygen, nitrogen, carbon, and boron in a greater variety of matrices have thus become analyzable with a higher reliability and efficiency.
Authors:Y. Kusaka, H. Tsuji, Y. Tamari, T. Sagawa, S. Ohmori, S. Imai, and T. Ozaki
A new radiochemical group separation method using APDC reagent in the extraction procedure has been developed. The method
has been applied to the radiochemical separation for activated biological samples and also to the preconcentration technique
for sea water samples. The transition elements are extracted into chloroform phase from the pH 3.0 aqueous phase and only
manganese is subsequently extracted from the pH 7.0 aqueous phase. The validity of the method is demonstrated by analyzing
the NBS standard reference materials. In the specimens preconcentrated from the sea water samples adjusted pH to 5.5, vanadium,
manganese, copper and zinc can be determined.
Authors:T. Fujinaga, Y. Kusaka, M. Koyama, H. Tsuji, T. Mitsuji, S. Imai, J. Okuda, T. Takamatsu, and T. Ozaki
A method is described for the determination of trace metal ions, V, Al, Cu, Mo Zn, and U, in natural water samples by neutron
activation analysis, using organic coprecipitation as a preconcentration method. The preconcentration of trace elements was
accomplished by converting the dissolved trace metal ions into the oxine chelates atpH 5.2 and extraction of the chelates witho-phenylphenol which is a liquid above 56 °C and solidifies at room temperature. After cooling the extraction system, the fine
particles of the organic phase were collected on a millipore filter and the precipitate was air-dried in a clean environment.
The solid extract was wrapped up in a sheet of clean polyethylene and subjected to neutron irradiation in a reactor for less
than 10 min at a thermal flux of 2·1013 n·cm−2·sec−1. γ-Ray spectrometry by a coaxial Ge(Li) detector connected to a 1024-channel PHA was performed on the irradiated sample without
further chemical separation, and thus the ppb level concentration of the elements in natural water samples could be determined.
The fundamental study of the collection of the trace elements is also described.