Round Robin test for the determination of nitrogen concentration in solid lithium

Favuzza, P.*; Antonelli, A.*; Furukawa, Tomohiro  ; Groeschel, F.*; Heidinger, R.*; Higashi, Takuma*; Hirakawa, Yasushi ; Iijima, Minoru; Ito, Yuzuru; Kanemura, Takuji; Knaster, J.*; Kondo, Hiroo; Micciche, G.*; Niiti, F.*; Ohira, Shigeru*; Severi, M.*; Sugimoto, Masayoshi*; Suzuki, Akihiro*; Traversi, R.*; Wakai, Eiichi  

Three different partners, ENEA, JAEA and University of Tokyo, have been involved during 2014 and 2015 in the Round Robin experimentation for the assessment of the soundness of the analitycal procedure for the determination of the Nitrogen impurities contained inside a solid Lithium sample. Two different kinds of Lithium samples, differing by about an order of magnitude in Nitrogen concentration (about 230 wppm, about 20-30 wppm), have been selected for this cross analysis. The agreement of the achieved results appears very good for what concerns the most concentrated Lithium and indicates each partner's procedure is appropriate and intrinsically able to lead to meaningful values, characterized by a relative uncertainty of just few %. The smaller agreement in the case of the less concentrated Lithium anyway points out that particular attention must be paid to reduce as much as possible any source of external contamination and highlights the importance of the proper blank subtraction.