We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
An improved CeO<sub>2</sub> method for high-precision measurements of <sup>17</sup>O/<sup>16</sup>O ratios for atmospheric carbon dioxide.
- Authors
Mahata, Sasadhar; Bhattacharya, Sourandra K.; Wang, Chung-Ho; Liang, Mao-Chang
- Abstract
RATIONALE The oxygen isotopic composition of carbon dioxide originating at the Earth's surface is modified in the stratosphere by interaction with ozone which has anomalous oxygen isotope ratio (Δ17O = 1000 * ln(1 + δ17O/1000) - 0.522 * 1000 * ln (1 + δ18O/1000) >0). The inherited anomaly provides a powerful tracer for studying biogeochemical cycles involving CO2. However, the existing methods are either too imprecise or have difficulty in determining the small Δ17O variations found in the tropospheric CO2. In this study an earlier published CeO2 and CO2 exchange method has been modified and improved for measuring the Δ17O values of atmospheric carbon dioxide with high precision. METHODS The CO2 fraction from air samples was separated by cryogenic means and purified using gas chromatography. This CO2 was first analyzed in an isotope ratio mass spectrometer, then artificially equilibrated with hot CeO2 to alter its oxygen isotopes mass-dependently and re-analyzed. From these data the 17O/16O and 18O/16O ratios were calculated and the Δ17O value was determined. RESULTS The validity of the method was established in several tests by using artificially prepared CO2 with zero and non-zero Δ17O values. The published value of the CO2-H2O equilibrium slope was also reproduced. CONCLUSIONS The CO2-CeO2 equilibration method has been improved to measure the oxygen isotope anomaly (Δ17O value) of atmospheric CO2 with an analytical precision of ±0.12‰ (2σ). Copyright © 2012 John Wiley & Sons, Ltd.
- Publication
Rapid Communications in Mass Spectrometry: RCM, 2012, Vol 26, Issue 17, p1909
- ISSN
0951-4198
- Publication type
Article
- DOI
10.1002/rcm.6296