The behavior of
88
Y,
152
Eu,
228
Ac,
241
Am, and
244
Cm was studied with 2-thenoyltrifluoroacetone resin with batch uptake, kinetics and column studies. Studies were performed in acetate buffer ...solutions (pH ~ 2 to ~ 6) and there was high uptake of all isotopes, except
228
Ac, at pH > 4.5. The kinetics of uptake were reasonable, although slower for the actinides, and sufficient for column studies. The retention of
88
Y,
152
Eu, and
241
Am on the resin in column studies was demonstrated as well as a reasonable separation of these isotopes from
228
Ac.
The uptake behavior of
88
Y,
140
Ba,
140
La,
141
Ce,
152
Eu,
228
Ac, and
241
Am was studied with batch uptake, kinetics and column studies in a synergistic extraction system with Pb resin and ...2-thenoyltrifluoroacetone in acetate-ethanol solutions. The k′ values are very high (> 10,000) at near neutral pH (~ 5 to 6) for all of the radioisotopes studied. The kinetics are reasonably fast for column separations, though the uptake rate is dependent on the concentration of 2-thenoyltrifluoroacetone. Column studies were performed to demonstrate the separation of the trivalent actinides and lanthanides from barium and common fission products (
99
Mo,
103
Ru).
The extraction of
224
Ra and
228
Ac with dibenzo-21-crown-7 resin was studied in solutions with Rose Bengal and identical solutions without Rose Bengal (blanks) from pH 3 to 12. Batch studies ...demonstrated that actinium is extracted at high pH (> 10) from both solutions but with a significantly higher extraction from the Rose Bengal solutions (maximum extraction ~ 60,000) than the blank solutions (maximum extraction ~ 2,000). In the Rose Bengal solutions, there was a weak extraction of actinium at lower pH (4–10) as well. There was no uptake of radium from the blank solutions, and a weak extraction at all pH levels from the Rose Bengal solutions. Kinetics studies were performed for actinium only, as radium had no significant extraction. Two column studies are demonstrated for the separation of radium from actinium. These separations are moderately effective with ~ 78% of the actinium recovered with no detectable radium.
The extraction of
73
As,
75
Se,
197m
Hg,
212
Pb and
210
Po on Eichrom pre-filter resin was studied in HCl and HNO
3
with batch uptake, kinetic and column experiments. There was significant extraction ...of mercury in HNO
3
and HCl, and polonium and selenium in HCl. The kinetics are sufficient to allow for retention on pre-filter columns, and separations of
73
As from
75
Se and
197m
Hg, and
212
Pb from
210
Po are demonstrated. This retention is important for the development of chemical separations as pre-filter resin is commonly used alongside extraction chromatography resins but its potential for uptake of metal ions is not well characterized.
Uptake of arsenic and selenium on iron-doped Pb resin Kmak, Kelly N.; Despotopulos, John D.; Scielzo, Nicholas D.
Journal of radioanalytical and nuclear chemistry,
02/2024, Letnik:
333, Številka:
2
Journal Article
Recenzirano
The uptake of the radioisotopes
73
As and
75
Se was characterized on Fe
3+
-doped Pb resin (Eichrom Technologies) from pH 1 to 12. There is good uptake of arsenic and selenium over a wide pH range (~ ...1 to 10) with a decrease only at high pH (~ 12). Column experiments were performed to demonstrate the separations of these elements from solutions with near neutral pH values (~ 6 to 8) with high yields and high radiopurity. These separations may be relevant for a wide variety of applications especially isotope harvesting research.
CL resin (TrisKem International) was characterized for separations of radium, actinium, thorium and protactinium. Batch studies are presented for radium, actinium and thorium in HCl and HNO
3
as well ...as for radium, thorium and protactinium in HF. The uptake of thorium from dilute HNO
3
(≤ 10
−4
M) and dilute HCl (≤ 10
−4
M) was found to be very high (
D
w
> 100 in HNO
3
and > 1000 in HCl). Kinetics studies on thorium were performed in HCl and HNO
3
to determine suitably for column separations. Six column separation studies are presented including the separation of trace thorium from radium and actinium in dilute HCl and HNO
3
, the separation of radium from 1 mg
232
Th in dilute HCl, the separation of thorium and radium in the presence of HCl and excess Cl
−
, the separation of radium, protactinium and thorium by retention of protactinium and the separation of protactinium and thorium by retention of thorium.
A procedure for the separation of technetium isotopes from bulk molybdenum was developed in nitric acid media. After irradiation of
nat
Mo foils, and dissolution in H
2
O
2
, the solution is ...acidified to 2 M HNO
3,
and anion exchange resin is used to separate technetium from molybdenum. The procedure is simple, requiring only basic laboratory equipment and, with a two-column separation, the technetium yield is high (~ 85%) with extremely high purity (< 0.1 ppm
nat
Mo). This is ideally suited for laboratory production of technetium tracer isotopes, particularly
95m
Tc.
The uptake behavior of
73
As and
75
Se was studied in HCl and HNO
3
media with CL resin, ethanethiol resin and dimethyl sulfide resin. In HCl solutions, there was high extraction of selenium on CL ...resin and ethanethiol resin but lower uptake on dimethyl sulfide resin; arsenic was only extracted by CL resin. From HNO
3
, selenium was extracted only by ethanethiol resin and CL resin and there was no uptake of arsenic on any resin. While the sulfur-based resins have high selenium uptake and selectivity, column separations are challenging due to the chemical instability of these resins.
The uptake of
75
Se and
73
As on trioctylamine-impregnated resin from HCl solutions was studied with batch uptake, kinetics, and column studies. Selenium-75 extracts well (
D
w
~ 900) at high HCl ...concentrations (≥ 10 M) with and no extraction of
73
As at any HCl concentration. The uptake kinetics were slow with low extraction (
D
w
< 100) for time periods ≤ 15 min and no clear equilibrium achieved even after 24 h. Column studies were performed to characterize the separation of
75
Se and
73
As;
75
Se is retained from conc. HCl while arsenic is eluted with high yields and high radiopurity.
The uptake behavior of
73
As and
75
Se was studied in HCl and HNO
3
-H
2
O
2
solutions on commercial extraction chromatography resins (TEVA, TRU, DGA, and Pb resin). There was no uptake of
73
As or
...75
Se from HNO
3
media. From HCl, there was
75
Se uptake at high concentrations on all the resins and no uptake of
73
As. Separations of
75
Se and
73
As on these resins have high yields and high radiopurity for
73
As, but limited recovery of
75
Se. TRU and TEVA resin may have potential for use in isotope generators as
75
Se can be retained for at least 26 days with repeated elutions.
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