A combined gas chromatography/combustion/isotope ratio mass spectrometer (GC/C/IRMS) system was employed to develop a rapid and simple method for measuring δ13C of bubble methane collected from wetlands. In spite of incomplete combustion of methane to CO2, calibration using standard methane can provide reproducible data with accuracy of ±0.5‰. Duplicate analyses of two gaseous samples were successfully measured within 20 min.
