Published by Misasa Medical Center, Okayama University Medical School
Published by Misasa Medical Center, Okayama University Medical School

<Formerly known as>
岡大三朝分院研究報告 (63号-72号) 環境病態研報告 (57号-62号)
岡山大学温泉研究所報告 (5号-56号) 放射能泉研究所報告 (1号-4号)

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渡辺 洵 東京大学理学部地質学教室
松葉谷 治 岡山大学温泉研究所温泉化学部門
Oxygen and carbon isotopic ratios of two working standards of our laboratory and three other standards were measured by McCrea's technique and the new McKINNEY type mass spectrometer in this Institute. The reproducibility of δ(13)C measurement is about ±0.2‰. Some systematic differences in δ(18)O values were observed among the three measurements in Apr.-May, July, and Aug., 1971. Because these systematic differences are supposed to be caused by the imperfection in the processes of decomposition of carbonates by phosphoric acid, the reproducibility of δ(18)O measurement may be ±O.2‰ in most cases. The calibrations of our working standard, CK-13, against the PDB standard were carried out on the assumption that δ(18)O and δ(13)C of CK-13 are -1.75‰ and +O.54‰ relative to PDB, respectively. The accuracy of these calibrations is about ±O.2‰ as shown by the interlaboratory comparison of some standards (Table 3). The δ(18)O values of the two working standards relative to PDB are independently recalculated relative to SMOW based on the two assumptions (Table 4). One of which is that a standard water MSA-2 is -8.20‰ relative to SMOW, and the other is that the δ(18)O of CK-13 is -1.75‰ relative to PDB. The results of both calculations agree within 0.4‰.
原著論文 (Original Paper)