Jenny Halleröd

Gamma-Radiolytic Stability of Solvents Containing C5-BPP (2,6-Bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine) for Actinide(III)/Lanthanide(III) Separation

ABSTRACT The stability of solvents containing the C5-BPP (2,6-Bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine) extractant against gamma-irradiation up to 330 kGy adsorbed dose was evaluated using HPLC mass spectrometric and solvent extraction methods. The main radiolysis products were identified using high-resolution mass spectrometry. Quantitative analysis of the residual C5-BPP concentration in irradiated samples was accomplished by a specifically developed MRM (Multiple Reaction Monitoring) method. A mixture of C5-BPP with 2-bromohexanoic acid in kerosene and 1-octanol, which had been used in an actinide(III)/lanthanide(III) separation process demonstration test, was also studied for its radiolytic stability and a remarkable protective effect of the presence of nitric acid during irradiation was found.

Development of the Chalmers Grouped Actinide Extraction Process

Abstract Several solvents for Grouped ActiNide EXtraction (GANEX) processes have been investigated at Chalmers University of Technology in recent years. Four different GANEX solvents; cyclo-GANEX (CyMe4- -BTBP, 30 vol.% tri-butyl phosphate (TBP) and cyclohexanone), DEHBA-GANEX (CyMe4-BTBP, 20 vol.% N,N-di-2(ethylhexyl) butyramide (DEHBA) and cyclohexanone), hexanol-GANEX (CyMe4-BTBP, 30 vol.% TBP and hexanol) and FS-13-GANEX (CyMe4-BTBP, 30 vol.% TBP and phenyl trifluoromethyl sulfone (FS-13)) have been studied and the results are discussed and compared in this work. The cyclohexanone based solvents show fast and high extraction of the actinides but a somewhat poor diluent stability in contact with the acidic aqueous phase. FS-13-GANEX display high separation factors between the actinides and lanthanides and a good radiolytic and hydrolytic stability. However, the distribution ratios of the actinides are lower, compared to the cyclohexanone based solvents. The hexanol-GANEX is a cheap solvent system using a rather stable diluent but the actinide extraction is, however, comparatively low.

Shelf-Life of ɛ-Lysyl-3-(Trimethylstannyl)Benzamide Immunoconjugates, Precursors for 211At Labeling of Antibodies

Astatine-211 is possibly the most promising radionuclide for targeted α-particle therapy when it comes to the treatment of occult disseminated cancer. Preclinical research has proven effective, and patient studies have been initiated based on these results. However, a lack of production capacity and the complex radiochemistry of (211)At are major obstacles for research and prospective clinical applications. In the present study, astatination of immunoconjugates, already prepared well in advance before radiolabeling, was performed to investigate the possibility of formulating a kit-like reagent for the production of (211)At radiopharmaceuticals. The shelf-life of ɛ-lysyl-3-(trimethylstannyl)benzamide immunoconjugates was evaluated, that is, the effect of different storage times on the quality of the immunoconjugates. The quality being referred to is the capacity to maintain a good radiochemical yield and good cell-binding property after labeling with (211)At. The stability of the conjugates was found to be pH dependent with high stability at pH≥7 and less stability at pH≤5.5. The immunoconjugates (based on trastuzumab) could be kept for more than 3 months in a phosphate buffered saline solution (pH 7.4) at 4°C before labeling, without compromising the quality of the labeled product. The conjugates are also unaffected by storage at -20°C. Conjugates with a good shelf-life compatible with distant shipping as well as improved radiochemistry are important steps to facilitate further clinical progress with (211)At.

On the Basic Extraction Properties of a Phenyl Trifluoromethyl Sulfone-Based GANEX System Containing CyMe4-BTBP and TBP

ABSTRACT A Grouped ActiNide EXtraction (GANEX) process for the extraction of actinides from used nuclear fuel for transmutation purposes has been investigated. The studied solvent consists of phenyl trifluoromethyl sulfone (FS-13), CyMe4-BTBP, and TBP, a combination that has previously shown promising results. The time to reach extraction equilibrium for the system has been found to be less than 20 min. A 2:1 complex has been found between CyMe4-BTBP and americium(III) or curium(III), whereas plutonium(IV) and CyMe4-BTBP create a 1:1 complex. The extraction of fission product is low in the system.