Field-Derived Microcosm Study of Stable Carbon Isotope Fractionation during Degradation of 1,2,4-Trichlorobenzene(Abstract)

摘要

Compound-specific isotope analysis (CSIA) has proven an effective means of identi- fying, and in some cases quantifying, the microbial degradation of organic contaminants. CSIA employs the use of gas chromatography-combustion-isotope ratio mass spectrome- try (GC-C-IRMS) to separate compounds, and to assess the isotopic fractionation of parent and daughter compounds. Stable carbon isotope fractionation (or a change in 13C/12C ratio of a compound) occurs during biodegradation due to bonds incorporating the light isotope (12C) transforming at a slightly faster rate than bonds incorporating the heavy isotope (13C). A variety of environmental contaminant classes (including petro- leum hydrocarbons, chlorinated ethenes and ethanes) have been shown to exhibit a char- acteristic enrichment in the heavy isotope (13C) as they undergo biodegradation due to this fractionation.