Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acs.est.9b06139
Document author version
Title (Primary) Chlorine isotope fractionation of the major chloromethane degradation processes in the environment
Author Keppler, F.; Barnes, J.D.; Horst, A.; Bahlmann, E.; Luo, J.; Nadalig, T.; Greule, M.; Hartmann, S.C.; Vuilleumier, S.
Journal Environmental Science & Technology
Year 2020
Department ISOBIO
Volume 54
Issue 3
Page From 1634
Page To 1645
Language englisch
Abstract Chloromethane (CH3Cl) is an important source of chlorine in the stratosphere, but detailed knowledge of the magnitude of its sources and sinks is missing. Here, we measured the stable chlorine isotope fractionation (εCl) associated with the major abiotic and biotic CH3Cl sinks in the environment, namely, CH3Cl degradation by hydroxyl (·OH) and chlorine (·Cl) radicals in the troposphere and by reference bacteria Methylorubrum extorquens CM4 and Leisingera methylohalidivorans MB2 from terrestrial and marine environments, respectively. No chlorine isotope fractionation was detected for reaction of CH3Cl with ·OH and ·Cl radicals, whereas a large chlorine isotope fractionation (εCl) of −10.9 ± 0.7‰ (n = 3) and −9.4 ± 0.9 (n = 3) was found for CH3Cl degradation by M. extorquens CM4 and L. methylohalidivorans MB2, respectively. The large difference in chlorine isotope fractionation observed between tropospheric and bacterial degradation of CH3Cl provides an effective isotopic tool to characterize and distinguish between major abiotic and biotic processes contributing to the CH3Cl sink in the environment. Our findings demonstrate the potential of emerging triple-element isotopic approaches including chlorine to carbon and hydrogen analysis for the assessment of global cycling of organochlorines.
Persistent UFZ Identifier
Keppler, F., Barnes, J.D., Horst, A., Bahlmann, E., Luo, J., Nadalig, T., Greule, M., Hartmann, S.C., Vuilleumier, S. (2020):
Chlorine isotope fractionation of the major chloromethane degradation processes in the environment
Environ. Sci. Technol. 54 (3), 1634 - 1645