Abstract: Objective The stability of ketamine in biological samples was studied under different storage temperature and time. Methods The rabbits were given intragastric administration of ketamine with a dose of 150 mg/kg and were sacrificed after 30 minutes. Blood, liver, kidney and brain of the rabbits were stored at room temperature (between 18 ℃ and 24 ℃) and -20 ℃. The specimens were analyzed at different times by GC-MS and GC-NPD. Results At -20 ℃, the concentration of ketamine decreased in all of samples (P<0.05) within 30 days. The concentration of ketamine increased in all of samples stored at room temperature after 5 days(P<0.05). Conclusion The stability of ketamine in biological samples stored at-20 ℃ was better than that at room temperature. The samples suspected containing ketamine should be stored at-20 ℃ and should be tested as soon as possible.

Key words: forensic toxicology, ketamine, stability, rabbits