Oxygen Isotope Exchange between O_2 and CO_2 over Hot Platinum: An Innovative Technique for Measuring Δ~(17)O in CO_2

摘要

The isotopic composition of carbon dioxide provides a powerful tool and has been widely used for constraining the sources and sinks of atmospheric CO_2. In this work, we demonstrate a simple, rapid, and clean way for measuring the triple oxygen isotope ratio of carbon dioxide with high precision. The method depends on isotope exchange between O_2 and CO_2 in the presence of platinum at high temperature and allows rapid measurement of Δ~(17)O of CO_2. The method has been established and confirmed through several tests by using artificially made CO_2 with known Δ~(17)O values. The analytical precision obtained for determining Δ~(17)O in CO_2 is 0.045‰ (1 - σ standard deviation).