Abstract
A new GC-Pyrolysis-IRMS method was developed for the δ13C determination of carboxyl carbon in low-molecular weight organic acids. By utilizing a palladium-wire reactor at 600 °C with a helium/hydrogen reactant gas, the carboxyl carbon of low-molecular weight organic acids is pyrolytically cleaved and introduced into an IRMS for stable carbon-isotope analysis. The precision of the GC-Py-IRMS method is similar to that of more conventional, combustion-based continuous-flow IRMS techniques and interpretation of isotope-dilution experiments with acetic and octanoic acid shows that the technique is sufficiently accurate for the determination of δ13C values at natural abundance levels. As a demonstration of this new capability, the carboxyl carbon of low-molecular weight (LMW, C2-C6) organic acids generated via hydrous pyrolysis of an oil-prone source rock (the Ghareb Shale) shows δ13C values consistent with the hypothesis that organic acids readily undergo exchange of their carboxyl carbon with aqueous inorganic carbon.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 161-168 |
| Number of pages | 8 |
| Journal | Organic Geochemistry |
| Volume | 33 |
| Issue number | 2 |
| DOIs | |
| State | Published - Mar 12 2002 |
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All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology
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Gas chromatography-pyrolysis-isotope ratio mass spectrometry : A new method for investigating intramolecular isotopic variation in low molecular weight organic acids. / Dias, Robert F.; Freeman, Katherine Haines; Franks, Stephen G.
In: Organic Geochemistry, Vol. 33, No. 2, 12.03.2002, p. 161-168.Research output: Contribution to journal › Article
TY - JOUR
T1 - Gas chromatography-pyrolysis-isotope ratio mass spectrometry
T2 - A new method for investigating intramolecular isotopic variation in low molecular weight organic acids
AU - Dias, Robert F.
AU - Freeman, Katherine Haines
AU - Franks, Stephen G.
PY - 2002/3/12
Y1 - 2002/3/12
N2 - A new GC-Pyrolysis-IRMS method was developed for the δ13C determination of carboxyl carbon in low-molecular weight organic acids. By utilizing a palladium-wire reactor at 600 °C with a helium/hydrogen reactant gas, the carboxyl carbon of low-molecular weight organic acids is pyrolytically cleaved and introduced into an IRMS for stable carbon-isotope analysis. The precision of the GC-Py-IRMS method is similar to that of more conventional, combustion-based continuous-flow IRMS techniques and interpretation of isotope-dilution experiments with acetic and octanoic acid shows that the technique is sufficiently accurate for the determination of δ13C values at natural abundance levels. As a demonstration of this new capability, the carboxyl carbon of low-molecular weight (LMW, C2-C6) organic acids generated via hydrous pyrolysis of an oil-prone source rock (the Ghareb Shale) shows δ13C values consistent with the hypothesis that organic acids readily undergo exchange of their carboxyl carbon with aqueous inorganic carbon.
AB - A new GC-Pyrolysis-IRMS method was developed for the δ13C determination of carboxyl carbon in low-molecular weight organic acids. By utilizing a palladium-wire reactor at 600 °C with a helium/hydrogen reactant gas, the carboxyl carbon of low-molecular weight organic acids is pyrolytically cleaved and introduced into an IRMS for stable carbon-isotope analysis. The precision of the GC-Py-IRMS method is similar to that of more conventional, combustion-based continuous-flow IRMS techniques and interpretation of isotope-dilution experiments with acetic and octanoic acid shows that the technique is sufficiently accurate for the determination of δ13C values at natural abundance levels. As a demonstration of this new capability, the carboxyl carbon of low-molecular weight (LMW, C2-C6) organic acids generated via hydrous pyrolysis of an oil-prone source rock (the Ghareb Shale) shows δ13C values consistent with the hypothesis that organic acids readily undergo exchange of their carboxyl carbon with aqueous inorganic carbon.
UR - http://www.scopus.com/inward/record.url?scp=0036190457&partnerID=8YFLogxK
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U2 - 10.1016/S0146-6380(01)00141-3
DO - 10.1016/S0146-6380(01)00141-3
M3 - Article
VL - 33
SP - 161
EP - 168
JO - Organic Geochemistry
JF - Organic Geochemistry
SN - 0146-6380
IS - 2
ER -