A STUDY ON THE SAMPLE PREPARATION TECHNIQUES TO IMPROVE VARLATION ANALYSIS OF ENVIRONMENTAL RADIOACTIVITIES IN AOMORI PREFECTURE

为了开展环境放射性、~（13）C和~（13）氚的变化分析，研究了样品制备技术<14>。在&lt;@D114@&gt;D1C定年中，样品经几种化学反应合成苯。由于样品制备过程中需要大量的工作，我们提出了另一种快速制备方法，即将碳化样品直接与熔融金属锂反应生成碳化锂。虽然碳化样品生成乙炔气的产率很低，但由于碳化样品的化学反应过程中存在的一些问题，本文提出了一种新的快速制备方法。52.5（]SY.+-. [)1.5在连续工艺中，乙炔合成苯的收率可达90%以上。用常规方法制备的样品的D1C年龄与用常规方法制备的样品的D1C年龄在10的年龄误差范围内是一致的。由于本方法不包括燃烧和随后的碳酸化过程，因此大大缩短了样品的制备时间。这一结果已在放射性同位素上证实（vol.47，NO.3，1998）.近年来，环境水样中的氚浓度有时显示1Bq/1或更低，这接近闪烁计数系统的探测极限.我们研制了一种利用固体聚合物电解膜电解法进行氚富集的装置，得到的氚回收率为80%除上述研究外，我们还发表了一篇关于<14>收集自青森县六所村地区的农产品和海产品的~（13）C特性的论文，我们还报道了一次关于~（13）C特性的会议，收集了青森县东部地区环境沃茨样品中的氚浓度。

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.