HR: 0800h
AN: A21B-0726    [Abstracts]
TI: Rapid and Simple quantifying system for $^{17}$O anomaly in CO$_{2}$ by using CF/IRMS
AU: * Kawagucci, S
EM: boss@ep.sci.hokudai.ac.jp
AF: Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, 060-0810, Japan, Sapporo, 060-0810 Japan
AU: Tsunogai, U
AF: Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, 060-0810, Japan, Sapporo, 060-0810 Japan
AU: Nakagawa, F
AF: Division of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, N10 W8, Kita-ku, Sapporo, 060-0810, Japan, Sapporo, 060-0810 Japan
AU: Honda, H
AF: Japan Space Exploration Agency, Sagamihara, Japan, Sagamihara, 229-8510 Japan
AU: Aoki, S
AF: Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University,, Sendai, Japan, Sendai, 980-8578 Japan
AU: Nakazawa, T
AF: Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku University,, Sendai, Japan, Sendai, 980-8578 Japan
AU: Gamo, T
AF: Ocean Research Institute, The University of Tokyo, Minamidai, Nakano-ku, Tokyo, Tokyo, 164-8639 Japan
AB: We developed a rapid and simple measurement system for $\delta$$^{17}$O, $\delta$$^{18}$O and $\delta$$^{13}$C values in nmol quantities of CO$_{2}$ by using continuous-flow isotope ratio mass spectrometry. The analytical system consisted sequentially of an automatic sample injection system, a helium-purged automatic CO$_{2}$ purification line, a GC capillary, combustion oven, and CF/IRMS. One of the features of our system is that we use CO$_{2}$ molecule to determine the stable isotopic compositions including $\delta$$^{17}$O. The $\delta$$^{17}$O, $\delta$$^{18}$O and $\delta$$^{13}$C values of CO$_{2}$ in a sample are calculated from the mass ratios of both 45/44 and 46/44 of two different kinds of CO$_{2}$, that have been purified quantitatively from different aliquot of a sample. While one (rCO$_{2}$) flows directly into IRMS after GC separation, the other one (eCO$_{2}$) flows through 900degC CuO unit prior to the introduction into IRMS in order to exchange oxygen atoms in the sample CO$_{2}$ molecules with mass-dependent oxygen atoms in CuO. To improve analytical precision statistically, both rCO$_{2}$ and eCO$_{2}$ are introduced alternately to IRMS repeatedly. The standard deviation of 0.57$\permil$ for $\delta$$^{17}$O can be realized by 9 repeated cycles of the pair analysis, using as little as 7nmol CO$_{2}$ within 3 hour. Analytical blanks associated with the single CO$_{2}$ introduction are as small as 1pmol. Based on this system, we determined vertical distribution of $\delta$$^{17}$O values in CO$_{2}$ in the stratospheric air over Japan.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting