Abstract: PREPARATION OF 1-2-~3H(2-HYDROXY-3-METHOXYPROPYL-2-NITRO-1H-IMIDAZOLETian Yuan; Tian Shuhao;Han Peizhen; Wang Jintong(Institute of Rodiation Medicine, Chinese Academy of Medical Sciences, Tianjin 300192)Abstract:The synthesis of tritium-labelled miSOnidazole (3H-MISO) via the NaB3H4 reduction of 1-(3-(methoxy-2-oxopropyl)-2-niro-1H-imidazole is described. The obtained product is treated with silica gel Column，distillation and Sep-Pak C18 columm HPLC shows that the chemical purity of the productis more than 99． 9％ and its radiochemical purity is more than 97％． The specific activity of the product is 16． 05TBq／mol，as determined by HPLC and liquid scintillation counting． Keywords: NSB~3H_4;~3H-MISO; preparation