LIQUID-LIQUID EXTRACTION OF METAL IONS WITH AMIDO PODANDS

Abstract
The extraction properties of ami do podands 1 - 3_ have been investigated. The ether dicarboxylic acid diamide i shows a clear preference for the extration of rare earth metal ions Yb(III)-, La(III) and the alkaline-earth metal ions Ca(II), Sr(II) as well. Due to the presence of the carboxylic group the ether dicarboxylic acid monoamide, 2. extracts the ions of the 3d-elements Cu(II), Co(II) and Zn(II), too. High distribution ratios have been obtained mainly for soft and medium-hard transition metal ions with the N-alkyl imino diacetic acid diamide 3_. Under the experimentally chosen conditions, alkali metal ions such as Na(I) and K(I) are practically not extracted by the investigated amido podands.