Studies on the Stability constants of complexes between rare earth elements and ethylenediaminediacetic acid

몇가지 희토류원소와 Ethylenediaminediacetic acid간의 착물의 안정도상수 측정

The stability constants of complexes between rare earth elements(Yb, Dy, Sm, Nd, Pr, Ce, La) and ethylenediaminediacetic acid(EDDA) have been measured for the separation of rare earth elements by potentiometric method. The $pk_1s$ of $MA^+$ complexes are in the range of 8.80-6.72 and the $pk_2s$ of $MA_2^-$ complexes are in the range of 7.43-4.37. The magnitude sequences of the stability constants are the reverse of the ionic size of rare earth elements.