|Budget Amount *help
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1997 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1996 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1995 : ¥1,100,000 (Direct Cost : ¥1,100,000)
I studied samoie preparation techniques to develop the variation analysis of the environmental radioactivities, ^<14>C and tritium.
In <@D114@>D1C dating, benzene is synthesized from collected samoles via severai chemical reactions.Since a great deal of efforts is required to the sample preparation, we proposed an another rapid process where the carbonized samples remples reacted to melted lithium metal directly to produze lithium zarbide .Although the yield generating acetylene gas from cardonized samoles was apparenyly low, 52.5(]SY.+-。[)1.5% on average, the yield synthesizing benzene from acetylene was 90% or more in the successive process.<@D114@>D1C ages for the samoles prepared by the conventional method were agreed to those for the same sample prepared by the converitional method within the age variation corresponding to the statistical error of 1o.Since this method does not contain combustion and the following carbonating process, the sample preparation is fairly shortened.This result has been publishrd on RADIOISOTOPES(vol.47, NO.3,1998).
Recently tritium concentrations in environmental water samples somples sometimes show a vaiue of 1 Bq/1 or lower which is near the detection limit of the scintillation counting system used.To measure low tritium concentration, we developed a tritium enrichment device which employs electrolysis using solid polymer electrolytic film.The obtained tritium recovery factor was 80% or more even at the water volume reduction factor of 10.This device will be used to enrich environmental water samples such as precipitation, coastal seawater and so on, after adding some improvements to the device.
Excepting above mentioned study, we have published a paper concerning to ^<14>C specific of farm products and marine products collected from the Rokkasho Area in Aomori prefecture.We have also reported on a conference about tritium concentrations in environmental waters samples collected from the east area of Aomori prefecture.