Author(s): Z. Wang | J. E. Mak
Journal: Atmospheric Measurement Techniques Discussions
ISSN 1867-8610
Volume: 2;
Issue: 5;
Start page: 2689;
Date: 2009;
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Original page
ABSTRACT
A new simultaneous analysis technique for stable isotope ratios (δ13C and δ18O) of atmospheric carbon monoxide (CO) from ice core samples and small air samples is presented, based on an on-line cryogenic vacuum extraction followed by continuous-flow isotope ratio mass spectrometry (CF-IRMS). The CO extraction system includes two multi-loop cryogenic cleanup traps, a chemical oxidant for oxidation to CO2, a cryogenic collection trap, a cryofocusing unit, purification by gas chromatography, and subsequent injection into a Finnigan Delta Plus IRMS. Analytical precision of 0.2‰(±1σ) for δ13C and 0.6‰(±1σ) for δ18O can be obtained for 100 mL (STP) air sample with CO mixing ratio ranging from 60 to 140 ppbv (~268–625 pmol CO). Six South Pole ice core samples with depth ranging from 133 to 177 m are also processed for CO isotope analysis based on a wet extraction line attached to the above cryogenic vacuum system. This is the first report on measuring isotope ratios of CO in ice core samples.
Journal: Atmospheric Measurement Techniques Discussions
ISSN 1867-8610
Volume: 2;
Issue: 5;
Start page: 2689;
Date: 2009;
VIEW PDF
DOWNLOAD PDF Original pageABSTRACT
A new simultaneous analysis technique for stable isotope ratios (δ13C and δ18O) of atmospheric carbon monoxide (CO) from ice core samples and small air samples is presented, based on an on-line cryogenic vacuum extraction followed by continuous-flow isotope ratio mass spectrometry (CF-IRMS). The CO extraction system includes two multi-loop cryogenic cleanup traps, a chemical oxidant for oxidation to CO2, a cryogenic collection trap, a cryofocusing unit, purification by gas chromatography, and subsequent injection into a Finnigan Delta Plus IRMS. Analytical precision of 0.2‰(±1σ) for δ13C and 0.6‰(±1σ) for δ18O can be obtained for 100 mL (STP) air sample with CO mixing ratio ranging from 60 to 140 ppbv (~268–625 pmol CO). Six South Pole ice core samples with depth ranging from 133 to 177 m are also processed for CO isotope analysis based on a wet extraction line attached to the above cryogenic vacuum system. This is the first report on measuring isotope ratios of CO in ice core samples.
