Separation of 44Ti from proton irradiated scandium by using solid-phase extraction chromatography and design of 44Ti/44Sc generator system

• 44Ti (T1/2 63 a) is a generator for PET isotope 44Sc and can be produced via proton irradiation of Sc.
• ZR chromatography resin can be used for the separation of 44Ti from bulk scandium matrices.
• DGA resin can be used for fine purification of 44Ti.
• ZR resin has potential as a solid support for a 44Ti/44Sc generator.
• The final 44Sc product was DOTA chelated for radiopharmaceutical labeling.

Scandium-44 g (half-life 3.97 h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, 18F, due to its favorable decay parameters. One source of 44gSc is the long-lived parent nuclide 44Ti (half-life 60.0 a). A 44Ti/44gSc generator would have the ability to provide radionuclidically pure 44gSc on a daily basis. The production of 44Ti via the 45Sc(p,2n) reaction requires high proton beam currents and long irradiation times. Recovery and purification of no-carrier added (nca) 44Ti from scandium metal targets involves complex separation chemistry. In this study, separation systems based on solid phase extraction chromatography were investigated, including branched diglycolamide (BDGA) resin and hydroxamate based ZR resin. Results indicate that ZR resin in HCl media represents an effective 44Ti/44gSc separation system.