Multivalent metal ion extraction using diglycolamide-coated particles
A separation medium, a method for using that separation medium and an apparatus for selectively extracting multivalent cations such as pseudo-lanthanide, prelanthanide, lanthanide, preactinide or actinide cations from an aqueous acidic sample solution is described. The separation medium is preferably free-flowing and comprises particles having a diglycolamide (DGA) extractant dispersed onto an inert, porous support.
1. A separation medium comprising a diglycolamide extractant corresponding in structure to Formula I dispersed onto a porous inert resin or silica support,
wherein R 1 , R 2 , R 3 and R 4 are the same or different and are hydrido or hydrocarbyl groups such that R 1 +R 2 +R 3 +R 4 contains about 14 to about 56 carbon atoms.
2. The separation medium according to claim 1 wherein said resin is macroreticular.
3. The separation medium according to claim 1 wherein said tetra-substituted diglycolamide extractant comprises about 3 to about 50 weight percent of the total dry weight of the separation medium.
4. The separation medium according to claim 1 wherein R 1 +R 2 +R 3 +R 4 contains about 16 to about 40 carbon atoms.
5. A separation medium comprising a diglycolamide extractant corresponding in structure to Formula I dispersed onto a porous inert resin support, said diglycolamide comprising about 3 to about 50 weight percent of the total dry weight of the separation medium,
wherein R 1 , R 2 , R 3 and R 4 are the same or different and are hydrido or hydrocarbyl groups such that R 1 +R 2 +R 3 +R 4 contains about 16 to about 40 carbon atoms.
6. The separation medium according to claim 5 wherein each of R 1 , R 2 , R 3 and R 4 is a hydrocarbyl group.
7. The separation medium according to claim 5 wherein said diglycolamide extractant is present dissolved in an organic diluent having a boiling point of about 170 degrees to about 220 degrees C at atmospheric pressure.
8. The separation medium according to claim 7 wherein said diglycolamide extractant is present at about 0.1 to about 1.5 molar.
9. The separation medium according to claim 5 wherein said separation medium is present as free flowing particles.
10. The separation medium according to claim 5 wherein said diglycolamide extractant is present at about 10 to about 40 weight percent of the total dry weight of the separation medium.
11. A separation medium comprising a diglycolamide extractant corresponding in structure to Formula I dispersed onto a porous inert resin support, said diglycolamide comprising about 3 to about 50 weight percent of the total dry weight of the separation medium, said separation medium being present as free flowing particles,
wherein R 1 , R 2 , R 3 and R 4 are the same or different hydrocarbyl groups such that R 1 +R 2 +R 3 +R 4 contains about 16 to about 40 carbon atoms.
12. The separation medium according to claim 11 wherein each of R 1 , R 2 , R 3 and R 4 is an n-octyl group or a 2-ethylhexyl group.