title: Oxygen isotope ratio measurements on carbon dioxide generated by reaction of microliter quantities of biological fluids with guanidine hydrochloride.
mesh_terms: D001826:Body Fluids / Q000378:metabolism*; D002245:Carbon Dioxide / Q000096:biosynthesis*; D019791:Guanidine; D006146:Guanidines; D006801:Humans; D010104:Oxygen Radioisotopes
chemical_list: D006146:Guanidines; D010104:Oxygen Radioisotopes; D002245:Carbon Dioxide; D019791:Guanidine