【摘要】 为了准确评价环境生物中的氚水平,基于高温催化氧化的原理,建立了一套生物中有机结合氚(Organically Bound Tritium,OBT)的制样装置Pyrolyser高温分解熔炉,通过大量的条件实验,优化了OBT的制样条件,并对典型植物中OBT分析的不确定度进行了研究。结果表明,在该装置中OBT制备的最佳条件为通氧量100 m L·min-1、催化氧化温度800°C和氧化燃烧温度600°C,此时,植物样品中OBT的回收率可达85%以上。优化后高温分解熔炉的制样过程更加安全,样品燃烧氧化更加充分,完全满足环境植物中OBT的分析要求,可用于环境生物氚水平测量及评价。更多还原

【Abstract】 Background: In the environment tritium exists primarily as tritiated water(HTO). However, tritium can also be incorporated into organically bound tritium(OBT) in plants and animals, and the OBT of environmental organisms can reflect the environmental tritium level. Purpose: In order to accurately evaluate the level of tritium in the biological environment, the furnace of tritium-carbon oxidation burning-pyrolyser pyrolysis has been developed to analyze the OBT activity of environmental plant on the base of the principle of high temperature catalytic oxidation. Methods: In this paper, the preparation condition of the pyrolyser-furnace was optimized through a lot of experiments, and the uncertainty of OBT in typical plant was studied. Results: The results indicate that the optimum preparation conditions of OBT in plant are with the oxygen flow rate of the working tube at 100 m L·min-1, the catalytic oxidation temperature at 800 °C and the combustion temperature at 600 °C. At this point, the recovery rate of combustion for different samples was kept above 85%. Conclusion: The sample preparation process of optimized condition is more secure and the combustion of plant sample is more complete, which completely meet the requirement of OBT analysis in environmental plant, and this method can be used in the tritium level measurement and evaluation in the environmental organism.更多还原