T. Cecconie, H. Freiser
Mar 15, 1990
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0
Influential Citations
21
Citations
Journal
Analytical Chemistry
Abstract
The extraction behavior of lanthanum(III), praseodymium(III), europium(III), terbium(III), holmium(III), and ytterbium(III) from dilute chloride solutions into chloroform solutions containing tri-n-octylphosphine oxide (TOPO) was examined. The lanthanides were found to extract as hydroxide complexes of the form Ln(OH){sub 3}{center dot}nTOPO. The extraction selectivity for this system increases with increasing TOPO concentration, rivaling those for common acidic organophosphorus extractants in the TOPO concentration range 0.025-0.100 M and surpassing them at higher concentrations. When TOPO concentrations of 0.25 M or greater are employed, the extraction system is, overall, the most selective for lanthanide separations to date. This is the first report of the lanthanides extracting as hydroxide complexes.