We investigated a new method for the synthesis of [15O]CO and [15O]CO2 that did not require heating, which might be useful for rapid supply in clinical use. The target gas, N2 with a small amount of added CO, was irradiated with deuteron to give [15O]CO. The [15O]CO2 was produced by passing a mixture of the purified [15O]CO and dry O2 through a manganese dioxide–cupric oxide (MnO2–CuO) catalyst at room temperature. The chemical yields of [15O]CO and [15O]CO2 of the new method were 4.5±0.1 and 4.0±0.1 MBq/ml, respectively, and were higher than those of conventional methods (1.9±0.1 MBq/ml of [15O]CO and 3.6±0.1 MBq/ml of [15O]CO2). The radiochemical purities of both [15O]CO and [15O]CO2 were over 99.9%. Each quality of [15O]CO and [15O]CO2 was suitable for clinical PET. The new method would remarkably shorten the preparation time for [15O]CO and [15O]CO2 production. Namely, the start of inhalation of the [15O]gases is not restricted by the production procedure of [15O]CO and [15O]CO2.
