Automation and investigation of scandium separation from ionic contaminants using ion-exchange chromatography and electrochemical methods

Scandium radioisotopes can be used to perform diagnostics (positron emission tomography and single-photon emission computer tomography) and therapy on patients (theranostics) due to low toxicity, short half-lives, and stable decay products. 43, 44Sc and 47Sc can be produced from elements such as Ca, V, Ti by protons irradiation. CERN-MEDICIS facility can irradiate target materials with a proton beam of 1.4 GeV and off-line separate the produced mixture elements/isotopes by using a mass separation device. Samples which are collected on Al or Zn coated Au foils (alternatively – NaCl coated Al) still contain isobaric contaminants that have to be separated by chemical methods. In this document the update of methods and results of scandium (stable and radioactive) separation from contaminants are reported including a novel method of removing impurities by aqueous electrolysis of Sc/ impurity mixtures. Sample investigation has been conducted with ICP-MS PLASMAQUANT, XRF ThermoScientific Niton XL3t, SEM-FIB Zeiss XB 540, current, voltage, and temperature registration using Keithly 2000 multimeters. Radiation measurements conducted with Canberra Cryo-Pulse 5 plus GX4020 gamma spectroscope and radiameter ThermoScientific FH 40G-L10. A proposed schematic for an automized system shown as well as tests for a semi-automated system successfully completed. Electrochemical separation method shows application in contaminant removal (in aqueous media). 47Sc separation recoverability using ion-exchange DGA resin shows 81.4 ± 13.2 % for 3 mm Diba Omnifit Benchmark Microbore column and 75.9 ± 11.8 % for 5 mm Diba Omnifit EZ adjustable end-piece column. The actual radiochemical recoverability is estimated to be ~ 99.9 % (~ 95% if accounting for 5 - 6% left in Al foil bulk due to implantation).