A passive sampling method for radiocarbon analysis of soil respiration using molecular sieve

Citation

Garnett MH, Hartley I, Sommerkorn M & Wookey P (2009) A passive sampling method for radiocarbon analysis of soil respiration using molecular sieve. Soil Biology and Biochemistry, 41 (7), pp. 1450-1456. http://www.sciencedirect.com/science/journal/00380717; https://doi.org/10.1016/j.soilbio.2009.03.024

Abstract
Radiocarbon analysis of soil CO2 can provide information on the age, source and turnover rate of soil organic C. We developed a new method for passively trapping respired CO2 on molecular sieve, allowing it to be returned to the laboratory and recovered for C isotope analysis. We tested the method on a soil at a grassland site, and using a synthetic soil created to provide a contrasting isotopic signature. As with other passive sampling techniques, a small amount of fractionation of the 13C isotope occurs during sampling, which we have quantified, otherwise the results show that the molecular sieve traps a sufficiently large and representative sample of CO2 for C isotope analysis. Since 14C results are routinely corrected for mass-dependent fractionation, our results show that passive sampling of soil respiration using molecular sieve offers a reliable method to collect soil-respired CO2 for 14C analysis.

Keywords
Soil respiration; CO2; Radiocarbon; Molecular sieve; Atmospheric carbon dioxide Environmental aspects; Global environmental change; Climatic changes Arctic regions; Climatic changes Environmental aspects

Journal
Soil Biology and Biochemistry: Volume 41, Issue 7