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Multigas Leakage Correction in Static Environmental Chambers Using Sulfur Hexafluoride and Raman Spectroscopy

Jochum, Tobias ; Fischer, Joseph C. von ; Trumbore, Susan ; Popp, Jürgen ; Frosch, Torsten (2015)
Multigas Leakage Correction in Static Environmental Chambers Using Sulfur Hexafluoride and Raman Spectroscopy.
In: Analytical Chemistry, 87 (21)
doi: 10.1021/acs.analchem.5b03312
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

In static environmental chamber experiments, the precision of gas flux measurements can be significantly improved by a thorough gas leakage correction to avoid under- or overestimation of biological activity such as respiration or photosynthesis. Especially in the case of small biological net gas exchange rates or gas accumulation phases during long environmental monitoring experiments, gas leakage fluxes could distort the analysis of the biogenic gas kinetics. Here we propose and demonstrate a general protocol for online correction of diffusion-driven gas leakage in plant chambers by simultaneous quantification of the inert tracer sulfur hexafluoride (SF6) and the investigated biogenic gases using enhanced Raman spectroscopy. By quantifying the leakage rates of carbon dioxide (CO2), methane (CH4), and hydrogen (H2) simultaneously with SF6 in the test chamber, their effective diffusivity ratios of approximately 1.60, 1.96, and 5.65 were determined, each related to SF6. Because our experiments suggest that the effective diffusivity ratios are reproducible for an individual static environmental chamber, even under varying concentration gradients and slight changes of the chamber sealing, an experimental method to quantify gas leakage fluxes by using effective diffusivity ratios and SF6 leakage fluxes is proposed. The method is demonstrated by quantifying the CO2 net exchange rate of a plant–soil ecosystem (Mirabilis jalapa). By knowing the effective chamber diffusivity ratio CO2/SF6 and the measured SF6 leakage rate during the experiment, the leakage contribution to the total CO2 exchange rate could be calculated and the biological net CO2 concentration change within the chamber atmosphere determined.

Typ des Eintrags: Artikel
Erschienen: 2015
Autor(en): Jochum, Tobias ; Fischer, Joseph C. von ; Trumbore, Susan ; Popp, Jürgen ; Frosch, Torsten
Art des Eintrags: Bibliographie
Titel: Multigas Leakage Correction in Static Environmental Chambers Using Sulfur Hexafluoride and Raman Spectroscopy
Sprache: Englisch
Publikationsjahr: 3 November 2015
Verlag: ACS Publications
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Analytical Chemistry
Jahrgang/Volume einer Zeitschrift: 87
(Heft-)Nummer: 21
DOI: 10.1021/acs.analchem.5b03312
Kurzbeschreibung (Abstract):

In static environmental chamber experiments, the precision of gas flux measurements can be significantly improved by a thorough gas leakage correction to avoid under- or overestimation of biological activity such as respiration or photosynthesis. Especially in the case of small biological net gas exchange rates or gas accumulation phases during long environmental monitoring experiments, gas leakage fluxes could distort the analysis of the biogenic gas kinetics. Here we propose and demonstrate a general protocol for online correction of diffusion-driven gas leakage in plant chambers by simultaneous quantification of the inert tracer sulfur hexafluoride (SF6) and the investigated biogenic gases using enhanced Raman spectroscopy. By quantifying the leakage rates of carbon dioxide (CO2), methane (CH4), and hydrogen (H2) simultaneously with SF6 in the test chamber, their effective diffusivity ratios of approximately 1.60, 1.96, and 5.65 were determined, each related to SF6. Because our experiments suggest that the effective diffusivity ratios are reproducible for an individual static environmental chamber, even under varying concentration gradients and slight changes of the chamber sealing, an experimental method to quantify gas leakage fluxes by using effective diffusivity ratios and SF6 leakage fluxes is proposed. The method is demonstrated by quantifying the CO2 net exchange rate of a plant–soil ecosystem (Mirabilis jalapa). By knowing the effective chamber diffusivity ratio CO2/SF6 and the measured SF6 leakage rate during the experiment, the leakage contribution to the total CO2 exchange rate could be calculated and the biological net CO2 concentration change within the chamber atmosphere determined.

Freie Schlagworte: Leakage Correction, Sulfur Hexafluoride SF6, Diffusion, Environmental Gas Sensing, Ecological Gas Sensing, Gas Analysis, Nitrogen Cycle, Cavity Enhanced Raman Spectroscopy CERS, Calculation
Fachbereich(e)/-gebiet(e): 18 Fachbereich Elektrotechnik und Informationstechnik
18 Fachbereich Elektrotechnik und Informationstechnik > Biophotonik-Medizintechnik
Hinterlegungsdatum: 19 Jan 2024 10:19
Letzte Änderung: 19 Jan 2024 17:17
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