Analytical method for the determination of At using an -scintillation-camera system and thin-layer chromatography

Segawa, Mariko   ; Nishinaka, Ichiro*; Toh, Yosuke   ; Maeda, Makoto  

At is a candidate nuclide for alpha-targeted therapy. In order to use At as a pharmaceutical, the radioactivity and chemical forms of generated At are the most fundamental specifications that need to be analyzed prior to its medical use. However, previous methods of separately measuring the radioactivity and chemical forms are not adaptable to the medical use of At because they cause a severe loss of At and do not analyze all the chemical forms of At. Therefore, a new analytical method for both the radioactivity and chemical forms of generated At is urgently needed. Accordingly, in this study, we developed an experimental system optimized to simultaneously analyze both the radioactivity and chemical forms of a At solution to significantly shorten the analysis time; we experimentally verified the accuracy and capabilities of this system at the Japan Atomic Energy Agency. The experiments confirmed that the present system could analyze the radioactivity and all the chemical forms of At with an uncertainty of approximately 5% in the region higher than 150 Bq and that it was 200 times more sensitive than the conventional method using an imaging technique with an X-ray imaging plate. As a result, a new method for analyzing the radioactivity and chemical forms of At was successfully established and this method will meet the demands for alpha-targeted therapy using At. This method will contribute to promoting the stable supply of the medical use of At in the near future.