In this paper a study for the selection of an NPE (nonylphenol ethoxylates)—free cocktail is discussed in order to be used for our routine liquid scintillation counting measurements. The NPE are added in the REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)—list of amendments to Annex XIV, as chemicals which can’t be used anymore (Commission Regulation (EU) 2017/999). Nine NPE-free cocktails were bought from different producers and investigated with respect to the homogeneity, background level and influence on counting efficiency for different radionuclides. Several sample matrices were considered for direct measurement of ³H and ¹⁴C. Based on this study we could select the best cocktail which fulfills our requirements for routine analyses.

在本文中，我们讨论了选择无 NPE（壬基酚聚氧乙烯醚）混合物的研究，以便将其用于我们的常规液体闪烁计数测量。NPE 被添加到 REACH（化学品的注册、评估、授权和限制）——附件 XIV 的修订列表中，作为不能再使用的化学品（委员会条例 (EU) 2017/999）。从不同的生产商处购买了九种不含 NPE 的鸡尾酒，并就不同放射性核素的均匀性、背景水平和对计数效率的影响进行了调查。几个样品基质被考虑用于直接测量³ H 和¹⁴ C。根据这项研究，我们可以选择满足我们常规分析要求的最佳鸡尾酒。