A simple isolation of 211 At using an anion-exchange spin column method
- PDF / 1,289,624 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 21 Downloads / 196 Views
A simple isolation of 211At using an anion-exchange spin column method Shigeki Watanabe1 · Ichiro Sasaki1,2 · Satoshi Watanabe1 · Tatsuya Higashi3 · Noriko S. Ishioka1 Received: 7 August 2020 / Accepted: 22 September 2020 / Published online: 10 October 2020 © Akadémiai Kiadó, Budapest, Hungary 2020
Abstract This study demonstrated the availability of an anion-exchange spin column method for the isolation of astatine-211 (211At) from bismuth (Bi). 211At was isolated in medium-to-excellent recovery efficiencies when loading 211At with 8M HCl (75.3– 79.1%), and 8M HNO3 (35.9–54.3%). The processing time of the optimized protocol was about 40 minutes. A neutralized eluent afforded an 211At-labeled phenylalanine derivative even in the absence of oxidant (radiochemical yield: 75.4%). These results indicate the anion-exchange spin column is useful for the isolation of 211At and the following synthesis of astatinated compounds, which is the first to isolate 211At with an anion-exchange method. Keywords Astatine-211 · Radionuclide production · Wet chemistry isolation · Anion-exchange method · Astatination · Targeted alpha-particle therapy
Introduction Astatine-211 (211At) is one of the most promising alphaemitting radionuclides for targeted alpha-particle therapy (TAT), a potential approach to cancer therapy using alpha-emitting radionuclides for the following reasons: its half-life (7.21 h) is long enough to deliver its labeled compounds to a target tissue; high efficiency is expected because of high alpha-particle energy (5.98 MeV, and 7.59 MeV from its daughter polonium-211 [211Po]) and strategies for the labeling of clinically available radioiodine are also adaptable to the synthesis of astatinated radiopharmaceuticals [1–3]. In addition, fundamental research on At chemistry is also important for the
* Shigeki Watanabe [email protected] 1
Department of Radiation‑Applied Biology, Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 1233 Watanuki, Takasaki, Gunma 370‑1292, Japan
2
Division of Molecular Science, Graduate School of Science and Technology, Gunma University, 4‑2 Aramaki, Maebashi, Gunma 371‑8510, Japan
3
Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences, QST, 4‑9‑1 Anagawa, Chiba 263‑8555, Japan
development of astatinated radiopharmaceuticals because most of the chemical and physical properties of At remain unknown [3]. Therefore, the development of an isolation method that can readily obtain pure 211At is highly desirable so that 211At may be widely used for the abovementioned purposes. 211At has been mainly produced via the 209Bi(α,2n)211At reaction followed by isolation with dry distillation [4–8]. This production method, which uses simple procedures, provides sufficient amounts of 211At (up to the order of sub-GBq to GBq) with good recovery efficiencies. However, the dry distillation requires considerable effort to establish reliable isolation conditions becau
Data Loading...
