1998 年 44 巻 6 号 p. 428-441
We developed a method to analyze tritium activity in the individual components of Japanese rice wine (Sake), i.e., aqueous and organic (alcohol). This method consists of a series of analytical procedures including fractionation, alcohol-oxidation, tritium enrichment and radioactivity measurement. Specialized fractionation and oxidation systems were designed and the operation conditions were determined. The enrichment system and measurement method contained an electrolysis method using multiplate cells and liquid scintillation analysis as previously described. In the first step of the pre-examination using ethylalcohol, the tritium content was measured within ±5%. In subsequent analyses, the tritium contetn was measured in Sake produced in 1990-1996. The tritium concentration in the aqueous component was consistently higher in Sake produced in the northern regions (Hokkaido and Tohoku) than in the southern regions (Kyushu) and also higher in Sake produced in the regions on the side of the Sea of Japan than that of the Pacific Ocean. However, this trend became less apparent with time. The tritium concentraton in the organic component showed no relation to the area of production. In general, the tritium level in this component was twice the aqueous component.