2024-03-29T11:06:40Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00012836
2023-01-16T03:59:39Z
879:1183:1184:1312
Gas composition of a small amount of oxalic acid combusted in closed -tube system
封管法で微量のシュウ酸をガス化した場合のガス組成
後藤(桜井), 昌子
82934
南, 雅代
82935
三村, 耕一
82936
Goto, Akiko S.
82937
Minami, Masayo
82938
Mimura, Kouichi
82939
2009-03
The closed tube-combustion method is still a popular sample purification system for ^<14>C and δ^<13>C analysis though the NC elemental analyzer system is used for efficient analysis of them. Minami et al. (submitted) suggested that the carbon yield of oxalic acid tends to decrease in the closed tube-combustion method with falling amount of sample, and that the low carbon yield affects the ^<14>C content and δ^<13>C values. In this study, we analyzed gas compositions of a small amount of oxalic acid combusted in the closed-tube by gas chromatography to clarify the factor of decreasing carbon yield. 1mg, 2mg and 5mg of oxalic acids were combusted with 50mg CuO at 450℃, and the extracted gases were analyzed by Gas Chromatograph (Shimadzu GC/TCD-2014) at Nagoya University. Three kinds of gasses H2, CO, and C02 were detected from 1mg oxalic acid combustion, though H2 and CO volumes were very smaller than C02. The total volume of detected gases is about 60%, and its low yield indicates an existence of the other gas with about dozens percent. On the other hand, the sample gases of 2mg and 5mg oxalic acids show high gas yields, composing of mainly C02, except for negligible amount of CO in 2mg sample. The gas of 10mg oxalic acid, combusted without CuO, contains considerable percentage of H2 and CO together with C02, compared with the samples combusted with CuO. The gases of H2 and CO, which are extracted due to imperfect combustion of oxalic acid, could block C02 formation from oxalic acid. This study indicates that the amount of extracted C02 is probably controlled by a quantity of formic acid and water extracted together, which might be occur in a closed -tube under strange condition of very low pressure.
departmental bulletin paper
名古屋大学年代測定資料研究センター
2009-03
名古屋大学加速器質量分析計業績報告書
20
152
155
jpn