Solvent extraction of Tm(III) and In(III) with mixtures of N-benzoyl-N-phenylhydroxylamine and thenoyltrifluoroacetone

The extraction behaviour of Tm(III) and In(III) into chloroform solutions containing both N-benzoyl-N-phenylhydroxylamine (HB) and thenoyltrifluoroacetone (HA) has been investigated. The experimental results for indium can be accounted for quantitatively in terms of the extraction constants for InA3, InB3 and the statistically-calculated values for InA2B and InAB2. Thulium, on the other hand, has higher extractability than the theoretical values obtained from the extraction constants of TmA3 and TmB3 and the statistical values for TmA2B and TmAB2. The additional extractability is due to the formation of the addition compound TmA3·HB, which is the predominant extractable species at comparatively high acidities (pH=3·0). At higher pH the chelates TmA3 and TmB3, as well as TmA2B and TmAB2, are also contained in the organic phase.