Abstract:
In the preparation of
89Zr using a cyclotron to bombard a
89Y solid target, trace metal impurities such as Fe, Al, Zn, and Mg, along with unreacted
89Y, are present. Separation and purification are necessary for application in
89Zr-labeled radiopharmaceuticals. This study conducted the following work: the static distribution coefficients of Zr
4+, Y
3+, Fe
3+, Mg
2+, Zn
2+ and Al
3+ on hydroxamate-based resin were measured in hydrochloric acid and oxalic acid systems. The dynamic adsorption rates of these metal ions on the resin column were measured in hydrochloric acid. The breakthrough curves of Zr
4+ in the hydroxamate-based resin were determined in hydrochloric acid. The elution of Zr
4+ and Fe
3+ from the resin using oxalic acid as an eluent was measured. The purification process conditions were validated using ZrCl
4 simulated solution and trace amounts of
89Zr
4+. The hydroxamate-based resin does not adsorb Y
3+, Al
3+, Zn
2+, or Mg
2+ in HCl. In 2.0 mol/L to 4.0 mol/L HCl solution, the adsorption of Fe
3+ is poor, while the adsorption of Zr
4+ is good in 2.0 mol/L to 6.0 mol/L HCl solution. The hydroxamate-based resin hardly adsorbs Zr
4+ in oxalic acid solutions above 0.05 mol/L, and its adsorption capacity for Fe
3+ first increases and then decreases with higher oxalic acid concentrations, reaching the strongest capacity at 0.5 mol/L. Zr
4+ is adsorbed by the hydroxamate-based resin column in 2.0 mol/L to 6.0 mol/L HCl solution, with an adsorption rate exceeding 95%. As the HCl concentration increases to 8.0 mol/L, the adsorption rate drops to 61.42%. Y
3+, Al
3+, and Mg
2+ are hardly adsorbed in 2.0 mol/L to 8.0 mol/L HCl. Fe
3+ shows negligible adsorption in 2.0 mol/L to 4.0 mol/L HCl, but the adsorption rate increases to 15.69% at 8.0 mol/L HCl. Using 200 mg of hydroxamate-based resin meets the adsorption capacity requirements for Zr
4+ in the purification of
89ZrCl
4 solution. During Zr purification, a 0.10 mol/L to 1.00 mol/L oxalic acid solution can be chosen for elution, but it is difficult to wash off Fe with this solution.
89Zr mainly concentrates in the elution volume of 400 μL to
1200 μL, with a total recovery rate exceeding 85%. Y
3+, Al
3+, Zn
2+, and Fe
3+ remain in the adsorption effluent and washing solution, with no impurities adsorbed on the resin column. Zr is almost completely adsorbed on the resin column, and the elution liquid can effectively wash out Zr, with no overlap between Zr elution peaks and impurity peaks. Using hydroxamate-based resin columns, an efficient and rapid method is established for separating and purifying
89Zr from Y targets after cyclotron bombardment. Solutions containing Zr
4+, Y
3+, Fe
3+, Al
3+, Zn
2+, and Mg
2+ pass through the hydroxamate-based resin columns. Then, 2.0 mol/L HCl and deionized water are used sequentially to wash the columns, and finally, Zr
4+ adsorbed on the resin is eluted with 0.50 mol/L oxalic acid, resulting in a purified oxalic zirconium solution. Studies with stable isotopes and
89Zr tracers indicate that the process for purifying
89ZrCl
4 solution using hydroxamate-based resin is feasible, and the resin effectively removes Mg
2+, Fe
3+, Y
3+, Al
3+, and Zn
2+ from the
89ZrCl
4 solution.