Study On The Forensic Toxicokinetics Of Diazepam â… 

Objective1. To develop a postmortem redistribution model of diazepam in rat after rapid-poisoning.2. To study the distribution of diazepam in acute poisoned rats.3. To explore the postmortem redistribution of diazepam in acute poisoned rats.Methods1. Distribution study: The rats in experimental group are given intragastric administration of diazepam with a dose of 16mg·g-1, 2h later, they are executed by hypoxia method. Cardiac blood, liver, stomach, lung, spleen, cardiac, kidney, muscle and brain are taken out to detect diazepam. Rats in control group are given intragastric administration of physiologic saline, blood and tissues are taken out correspondingly and used as blank check.2. Postmortem redistribution study: The rats in experimental group are given intragastric administration of diazepam with a dose of 90mg·kg-1, 2h later, they are executed by hypoxia method and then they are preserved at temperatures of 20℃. Cardiac blood, liver, stomach, lung, spleen, cardiac, kidney, muscle and brain are taken out to detect diazepam at different times after death (0h, 2h, 4h, 8h, 12h, 24h, 48h, 72h, 96h ).3. Collection of samples: The samples of blood and tissues, to which internal standard object (aprobarbital) is added, are alkalified and extracted by aether. The extracts are quantitated by internal standard and working curve methods.4. Statistics method:the dates was handled by software SPSS11.5 and the result was expressed byResults1. The concentration of diazepam is comparatively higher in tissues and lower in blood. The concentration has significant difference(P<0.01).The sequence of diazepam content in rats is as follow : lung > liver> muscle > kidney > brain> cardiac > spleen >cardiac blood.2. The method of gas chromatogram: The study has established the methods of gas chromatogram in detecting diazepam detection. The linear range is 0.1-12μg/g orμg/mL , the minimum detectable concentration is 0.05μg/g orμg/mL, and the average of recovery rate exceeds 95% 3. Postmortem Redistribution: In 96 hour after rats death, the diazepam content is going up in cardiac blood, liver with time prolonging at temperatures of 20℃, the changing trend of diazepam content is ascending first and then descending in lung , cardiac ,kidney, spleen and no significant change can be seen in periphera brain and muscle.Conclusion1. The postmortem distribution and postmortem redistribution models of diazepam in rat were established, which can be applied to the forensic identification and the forensic toxicokinetics study of diazepam.2. Diazepam is generally distributed in blood and tissues of rats. Diazepam content in tissues is higher than that in blood.3. In the forensic expertise of diazepam poisoned death, heart-blood, peripheral blood and muscle should collect as the samples for the analysis, in the assessment of death cause, postmortem redistribution should be taken into consideration.