Fig. 9. CHN elemental analysis of the dried [P₆₆₆₁₄][NO₃] phase, after full loading by extraction of La³⁺, Pr³⁺, Nd³⁺, Eu³⁺, Ho³⁺, Er³⁺ and Lu³⁺ from a 3.5 mol L⁻¹ Ca(NO₃)₂ solution (4 : 1 A/O phase ratio, [Ln³⁺]_aq,in = 0.5 mol L⁻¹). The dashed line and the dotted line indicate the theoretical value of hexanitrato and pentanitrato complexes, respectively.