薄层层析法分离重稀土元素

The Sepration of the Heavy Rare-Earth Elements by Thin-Layer Chromatography

本文研究了在硅胶H/硝酸铵羧甲基纤维素钠(CMC)/HO(重量比为33:4:1:110)的薄层板上以体系Ⅰ:二-2-乙基己基磷酸-异丙醚-乙醚-硝酸和体系Ⅱ:单-2-乙基己基磷酸-异丙醚-乙醚-硝酸为展开剂测定稀土元素La、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y的Rf值,并研究了改变两体系中各组分比例对各稀土元素色谱行为的影响以及对分离效果的影响。当二-2-乙基己基磷酸-异丙醚-乙醚-硝酸的体积比(1:10:6:1.1)、单-2-乙基己基磷酸-异丙醚-乙醚-硝酸的体积比为(1:8:8:1.1)时,上述各稀土元素间均能表现出较明显的Rf值差异。分离La、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y稀土标准混合液,各元素的分离情况可达到定量测定要求,结果令人满意。在两种磷酸型萃取剂中,单-2-乙基己基磷酸比P204分离效果更好,稀土元素斑点清晰,不易拖尾,并且单-2-乙基己基磷酸合成简单,试剂价格便宜,因此是分离稀土元素较为理想的试剂。

Two thin-layer chromatographic methods are reported for the separation of the heavy rare-earth elements. Silica gel, ammonium nitrate and CMC were used as stationary phase, di(2-ethylhexyl) phosphoric acid/isopropyl ether /ether /nitric acid (System I ) (v/v 1: 10:6:1.1) and mono(2-ethyl-hexyl) phosphoric acid/is-propyl ether/ether/nitric acid (System Ⅱ) (v/v 1:8:8:1.1) as developers. Using either the systemⅠor Ⅱ , La, Sm,Eu, Gd,Tb,Dy, Ho, Er,Tm, Yb,Lu, Y can be separated from each other, the separating efficiency of the system I is better.