Investigation On The Analytical Method Of Long-Lived Fission Product⁹⁹ Tc In Different Sample Matrix

With the exploiting of nuclear energy and the development of nuclear medical diagnosis,the total amount of technetium（Tc）in the environment increased continually.Because of the long half-life,high fission yield（about 6%）,and high mobility in the environment with the stable form of TcO4^-,⁹⁹Tc has caused widely attention in environmental safety assessment,biological effect and disposing nuclear waste.Analytical monitoring of ⁹⁹Tc content in various samples（environmental soil,human urine samples,nuclear fuel components,etc.）is more and more important.The low concentration of ⁹⁹Tc in the sample and the diversity of matrix result in the necessary pretreatment,separation,and purification steps before the quantification.The loss of technetium is inevitable during the above steps,thus choosing the appropriate treatment methods and tracers are the key to accurately determine the ⁹⁹Tc content.Based on the systematic summary of the source,physicochemical properties,biological effects and environmental behaviors towards technetium,this work focused on the feasibility of using Re as a tracer of Tc and the establishment of the separation and analysis method for ⁹⁹Tc in different samples.The results show that the chemical behavior of Re and Tc are basically the same in the steps of column separation,and measurement except redox coprecipitation.Since the ⁹⁹Tc separation analysis method is diverse,the characteristics of the matrix and the different contents of technetium in the sample should be taken into consideration before selecting the appropriate pretreatment,separation analysis and measurement methods.Finally,the separation and analysis method of ⁹⁹Tc content in different samples（environmental soil,human urine samples,UO₂ samples）are established.