Exchange with Oxygen Gas

Isotopic exchange with oxygen gas usually occurs on surfaces at fairly high temperatures (300-2000°C.). Isotopic exchange between oxygen gas with carbon dioxide occurs only above 800°C. (Bank, 1958). The exchange of oxygen with water at low temperature occurs only in the presence of radiation (Hart et al., 1953), free radicals (Kasarnowsky et al., 1956), or ozone (Forchheimer and Taube, 1954). 

If high concentrations of oxygen-18 are used, it should be noted that isotopic scrambling of oxygen molecules, known as homomolecular reactions, can occur at low temperatures under the influence of light, electric discharges, ozone, chlorine, or oxide surfaces (Ogg, 1953 Ogg and Sutphen, 1953 Johnston and O Shea, 1953). 

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