In this study, the recovery rates of the dissolution method for radioactivity analysis of expandable polystyrene (EPS) with a liquid scintillation counter (LSC) using tetrahydrofuran (THF), toluene, and acetone as solvents were estimated. The detection efficiency calibration curve for each solvent was derived. Two methods—the volumetric ratio method and the quenching agent method—were used to prepare quench source sets, and calibration curves were derived by linking the data from the two quench source sets. The R² value of the calibration curve for THF was found to be 0.984. The relationship between the mass of dissolved EPS and the quench level was estimated: the quench level increased as the mass of dissolved EPS increased. Premix and postmix dissolution methods were tested. The recovery rates using THF with the premix method were 84.9 ± 0.9% and 96.5 ± 1.5% for ³H and ¹⁴C, respectively. Furthermore, the stability of the recovery rate over time when using THF was evaluated. The dissolution method with the premixed solution exhibited a more stable recovery rate over time. The dissolution methods were found to be applicable for analysis using LSC, and THF was found to be the most suitable solvent for the proposed method.

在本研究中，以四氢呋喃 (THF)、甲苯和丙酮为溶剂，使用液体闪烁计数器 (LSC) 对可发性聚苯乙烯 (EPS) 进行放射性分析的溶解方法的回收率进行了评估。导出了每种溶剂的检测效率校准曲线。两种方法——体积比法和淬火剂法——用于制备淬火源组，并通过链接来自两个淬火源组的数据得出校准曲线。R ²发现 THF 的校准曲线值为 0.984。估计溶解的 EPS 的质量与淬火水平之间的关系：淬火水平随着溶解的 EPS 质量的增加而增加。测试了预混和后混溶出方法。对于³ H 和¹⁴ C，使用 THF 和预混方法的回收率分别为 84.9 ± 0.9% 和 96.5 ± 1.5% 。此外，还评估了使用 THF 时回收率随时间的稳定性。使用预混溶液的溶解方法随着时间的推移表现出更稳定的回收率。发现溶解方法适用于使用 LSC 进行分析，并且发现 THF 是最适合所提出方法的溶剂。