A new CF-IRMS system for quantifying stable isotopes of carbon monoxide from ice cores and small air samples
We present a new analysis technique for stable isotope ratios (δ 13 C and δ 18 O) of atmospheric carbon monoxide (CO) from ice core samples. The technique is an online cryogenic vacuum extraction followed by continuous-flow isotope ratio mass spectrometry (CF-IRMS); it can also be used with small ai...
| Published in: | Atmospheric Measurement Techniques |
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| Main Authors: | , |
| Format: | Text |
| Language: | English |
| Published: |
2018
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| Subjects: | |
| Online Access: | https://doi.org/10.5194/amt-3-1307-2010 https://amt.copernicus.org/articles/3/1307/2010/ |
| Summary: | We present a new analysis technique for stable isotope ratios (δ 13 C and δ 18 O) of atmospheric carbon monoxide (CO) from ice core samples. The technique is an online cryogenic vacuum extraction followed by continuous-flow isotope ratio mass spectrometry (CF-IRMS); it can also be used with small air samples. The CO extraction system includes two multi-loop cryogenic cleanup traps, a chemical oxidant for oxidation to CO 2 , a cryogenic collection trap, a cryofocusing unit, gas chromatography purification, and subsequent injection into a Finnigan Delta Plus IRMS. Analytical precision of 0.2‰ (±1δ) for δ 13 C and 0.6‰ (±1δ) for δ 18 O can be obtained for 100 mL (STP) air samples with CO mixing ratios ranging from 60 ppbv to 140 ppbv (~268–625 pmol CO). Six South Pole ice core samples from depths ranging from 133 m to 177 m were processed for CO isotope analysis after wet extraction. To our knowledge, this is the first measurement of stable isotopes of CO in ice core air. |
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