title: A simple infrared spectroscopic method for the measurement of expired 13CO2.
mesh_terms: D000818:Animals; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods*; D002244:Carbon; D002245:Carbon Dioxide / Q000032:analysis*; D002247:Carbon Isotopes; D008297:Male; D051381:Rats; D012119:Respiration; D013055:Spectrophotometry, Infrared
chemical_list: D002247:Carbon Isotopes; D002245:Carbon Dioxide; D002244:Carbon