title: Measurement of 13CO2/12CO2 abundance by nondispersive infrared heterodyne ratiometry as an alternative to gas isotope ratio mass spectrometry.
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D002250:Carbon Radioisotopes / Q000032:analysis; D013058:Mass Spectrometry; D013055:Spectrophotometry, Infrared
chemical_list: D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; D002245:Carbon Dioxide