# Towards a dry separation method of radioscandium from bulk amounts of titanium

## TL;DR

Researchers developed a method to separate radioscandium from titanium using heat and vacuum, achieving high release rates and modeling the process.

## Contribution

A novel dry separation method for radioscandium from titanium was developed and modeled with high efficiency.

## Key findings

- 99.9% of 47Sc was released from 50 μm Ti foil at 1100°C in vacuum.
- A Monte Carlo model determined the desorption energy of Sc from Ti surfaces as 390 ± 5 kJ/mol.
- Gold surfaces achieved the highest 47Sc recovery yield of 65%, while other materials showed lower yields.

## Abstract

True theranostic radionuclide pairs are gaining interest in nuclear medicine. However, their application is limited due to their reduced availability. 47Sc is a promising therapeutic partner to the diagnostic 43Sc and 44Sc due to its ideal half-life and beta energy. This study attempted to develop a dry, gas–solid phase separation of non-carrier-added radioscandium from macro amounts of titanium. The results showed a 99.9% release of 47Sc from Ti foil of 50 μm thickness at 1100 °C in vacuum. Furthermore, a Monte Carlo model was developed to describe the release of Sc from Ti as a function of temperature and foil thickness. With this model the desorption energy of Sc from Ti surfaces was determined to be 390 ± 5 kJ/mol in excellent agreement with theoretical predictions. In an attempt to recover the evaporated 47Sc on a cold finger, highest overall yields of 65% were observed for gold surfaces. For other catcher materials such as Ti, Ta, and brass significantly lower overall yields between 27 and 47% were determined. Furthermore, it was not possible to quantitatively remove the 47Sc from the Au catcher, even when washing with concentrated acids. Attempts to increase the release of scandium from thick, sintered Ti samples failed to show an improvement over solid titanium.