Journal article
Adapting an elemental analyser to perform high-temperature catalytic oxidation for dissolved organic carbon measurements in water
Rapid communications in mass spectrometry, e9451
12/2022
PMID: 36479758
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Source: InCites
Abstract
Many laboratories employ elemental analyzers (EA) coupled to isotope ratio mass spectrometers (IRMS) to measure carbon stable isotope ratios (δ13C) in solid samples. Dissolved organic carbon (DOC) in most natural water samples cannot be analyzed using this approach unless time consuming preconcentration is employed.
An EA-IRMS can be used to measure DOC δ13C in natural waters without the need for sample preconcentration by employing high-temperature catalytic oxidation. An autosampler injects water in the EA reactor at 680oC filled with platinum catalyst beads, where all carbon is converted to CO. Remaining water and halides are removed, while CO is trapped in a cryotrap and later released to the IRMS.
Measurements were accurate (deviation < 0.3 ‰ compared to solid sample measurements) and precise (error of 0.3 ‰ for concentrations ≥ 46 μM). Blanks were present and accounted for. Salinity up to seawater level did not affect accuracy or precision, but limited the number of samples that could be run before cleaning of the reactor was needed. DOC δ13C in a river/estuary varied between -25.7 and -23.2 ‰, with higher values for waters with higher salinity, as expected. Deep-sea water reference material had a value of -22.9 ± 0.5 ‰, very similar to those found in recent reports employing similar techniques.
Adapting an EA is a feasible approach for the measurement of DOC δ13C in natural waters. The low cost and simplicity of the system allow its use in any laboratory already equipped with EA-IRMS.
Details
- Title
- Adapting an elemental analyser to perform high-temperature catalytic oxidation for dissolved organic carbon measurements in water
- Creators
- Matheus C Carvalho - Southern Cross Analytical Research Services, Southern Cross University. Centre for Coastal Biogeochemistry, Southern Cross University, Lismore, NSW, Australia
- Publication Details
- Rapid communications in mass spectrometry, e9451
- Publisher
- John Wiley & Sons Ltd.
- Identifiers
- 991013072611202368
- Academic Unit
- Environmental Analysis Laboratory
- Language
- English
- Resource Type
- Journal article