|Title||Proton-induced production and radiochemical isolation of 44Ti from scandium metal targets for 44Ti/44Sc generator development|
|Publication Type||Journal Article|
|Year of Publication||2017|
|Authors||Radchenko, V, Engle, JW, Medvedev, DG, Maassen, JM, Naranjo, CM, Unc, GA, Meyer, CAL, Mastren, T, Brugh, M, Mausner, L, Cutler, CS, Birnbaum, ER, John, KD, F. Nortier, M, Fassbender, ME|
|Journal||Nuclear Medicine and Biology|
|Pagination||25 - 32|
|Keywords||Ion exchange chromatography, Proton irradiation, Scandium target, Ti, Ti/Sc generator|
Scandium-44g (half-life 3.97h) shows promise for application in positron emission tomography (PET), due to favorable decay parameters. One of the sources of 44gSc is the 44Ti/44gSc generator, which can conveniently provide this radioisotope on a daily basis at a diagnostic facility. Titanium-44 (half-life 60.0 a), in turn, can be obtained via proton irradiation of scandium metal targets. A substantial 44Ti product batch, however, requires high beam currents, long irradiation times and an elaborate chemical procedure for 44Ti isolation and purification. This study describes the production of a combined 175MBq (4.7mCi) batch yield of 44Ti in week long proton irradiations at the Los Alamos Isotope Production Facility (LANL-IPF) and the Brookhaven Linac Isotope Producer (BNL-BLIP). A two-step ion exchange chromatography based chemical separation method is introduced: first, a coarse separation of 44Ti via anion exchange sorption in concentrated HCl results in a 44Tc/Sc separation factor of 102–103. A second, cation exchange based step in HCl media is then applied for 44Ti fine purification from residual Sc mass. In summary, this method yields a 90–97% 44Ti recovery with an overall Ti/Sc separation factor of ≥106.