【摘要】 本文系统地研究了稀土与对氨基本基萤光酮（P-APF）及溴化十六烷基三甲铵（CT-AB）形成三元络合物的规律,结果表明,RE³⁺与P-APF、CTAB在不同pH范围可形成两种络合物,在pH7-9,形成橙红色络合物,摩尔吸光系数（ε）为7.50×10⁴1.25×10⁵l·mol^-1·cm^-1,λ_max为534—540nm;在pH>10.5,形成玫瑰红色络合物,ε值为1.30×10⁵—1.58×10⁵l·mol·cm^-1,λ_max为585—597。在三元络合体系中加入竞争配体NaF、EDTA,提高了体系的选择性,在NaF存在下,从La中回收Sm,在EDTA存在下,从La中回收Ce,结果的重现性较好。更多还原

【Abstract】 The color reactions of the ternary complexes of rare earths with para-aminophe-nylfluorone (P-APF) and cetyltrimethyl ammonium bromide (CTAB) have been studied. Two kinds of complexes are formed though these reactions. The absorption maxima of these ternary complexes appear at 534-540nm and 585-597nm respectively, and their molar absorptivities are (0.75-1.22)×1051·mol-1·cm-1 and (1.32-1.58)×1051·mol-1· cm-1 respectively. The composition of ternary complexes of La and Yb is La(Yb):P-APF:CTAB = 1:3:6. In the presence of NaF, ternary complexes of La, Ce and Pr cannot be formed, while the other rare earths complexes show higher stability under this condition. In the presence of EDTA, the cerium ternary complex displays higher stability, but the lanthanum ternary complex does not. A new method based on the above differences has been developed for the rapid determination of Sm-Lu in La or Ce or Pr in the presence of NaF and determination of Ce in La in the presence of EDTA.更多还原