Evaluation of Novel Wet Chemistry Separation and Purification Methods to Facilitate Automation of Astatine-­211 Isolation

Technical Report · Tue Jul 19 00:00:00 EDT 2016

DOI:https://doi.org/10.2172/1335515· OSTI ID:1335515

Wilbur, Daniel Scott ^[1]

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1. Univ. of Washington, Seattle, WA (United States)

This research is a collaborative effort between the research groups of the PIs, Dr. D. Scott Wilbur in the Department of Radiation Oncology at the University of Washington (UW) and Matthew O’Hara at the Pacific Northwest National Laboratory (PNNL). In this report only those studies conducted at UW and the budget information from UW will be reported. A separate progress and financial report will be provided by PNNL. This final report outlines the experiments (Tasks) conducted and results obtained at UW from July 1, 2013 thru June 30, 2016 (2-­year project with 1 year no-­cost extension). The report divides the information on the experiments and results obtained into the 5 specific objectives of the research efforts and the Tasks within those objectives. This format is used so that it is easy to see what has been accomplished in each area. A brief summary of the major findings from the studies is provided below. Summary of Major Findings from Research/Training Activities at UW: Anion and cation exchange columns did not provide adequate ²¹¹At capture and/or extraction results under conditions studied to warrant further evaluation; PEG-­Merrifield resins containing mPEG350, mPEG750, mPEG2000 and mPEG5000 were synthesized and evaluated; All of the mPEG resins with different sized mPEG moieties conjugated gave similar ²¹¹At capture (>95%) from 8M HCl solutions and release with conc. NH₄OH (~50-­80%), but very low quantities were released when NaOH was used as an eluent; Capture and release of ²¹¹At when loading [²¹¹At]astatate appeared to be similar to that of [²¹¹At]astatide on PEG columns, but further studies need to be conducted to confirm that; Capture of ²¹¹At on PEG columns was lower (e.g. 80-­90%) from solutions of 8M HNO₃, but higher capture rates (e.g. 99%) can be obtained when 10M HNO₃ is mixed with an equal quantity of 8M HCl; Addition of reductants to the ²¹¹At solutions did not appear to change the percent capture, but may have an effect on the % extracted; There was some indication that the PEG-­Merrifield resins could be saturated (perhaps with Bi) resulting in lower capture percentages, but more studies need to be done to confirm that; A target dissolution chamber, designed and built at PNNL, works well with syringe pumps so it can be used in an automated system; Preliminary semi-­automated ²¹¹At isolation studies have been conducted with full-scale target dissolution and ²¹¹At isolation using a PEG column on the Hamilton automated system gave low overall recoveries, but HNO₃ was used (rather than HCl) for loading the ²¹¹At and flow rates were not optimized; Results obtained using PEG columns are high enough to warrant further development on a fully automated system; Results obtained also indicate that additional studies are warranted to evaluate other types of columns for ²¹¹At separation from bismuth, which allow use of HNO₃/HCl mixtures for loading and NaOH for eluting ²¹¹At. Such a column could greatly simplify the overall isolation process and make it easier to automate.

• Research Organization: Univ. of Washington, Seattle, WA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: SC0010502
• OSTI ID: 1335515
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ASTATINE 211
SOLUTIONS
HYDROCHLORIC ACID
RESINS
NITRIC ACID
SODIUM HYDROXIDES
MATERIALS RECOVERY
AMMONIUM HYDROXIDES
EVALUATION
AUTOMATION
EXTRACTION
BISMUTH
PURIFICATION
FLOW RATE
ION EXCHANGE
BUDGETS
DESIGN
SEPARATION PROCESSES
astatine-211
radiopharmaceuticals