Separation of radiolanthanides by high performance liquid chromatography [abstract]

Abstract

Studies were carried out to develop a method for the separation of radiolanthanides using high performance liquid chromatography (HPLC). Radiolanthanides are essential for radiotherapy and/or imaging of cancer and their metastases. Specifically, a method was developed to separate lutetium-177 (177Lu) from samarium-153 (153Sm) using a cation-exchange column on the HPLC. 177Lu and 153Sm are obtained through neutron activation of 176Lu and 152Sm respectively at the University of Missouri-Columbia Research Reactor. A good separation of Lu-177/Sm-153 allowed us to decide on the selection and conditions of solvents to be used for other lanthanides. Additionally, studies were also carried out for the separation of promethium-149 (149Pm) from cold neodymium-148 (147Nd used as a radioactive trace). As Pm and Nd are located next to each other on the periodic table their very similar chemical properties pose a challenge in performing a complete separation. For example, varying the concentration and pH of solvents, ?-hydroxy-?- methylbutyric acid (?-H-? -MBA) and ?-hydroxy isobutyric acid (?-HIBA), can effectively produce good chromatographic separation of the lanthanides. High purity germanium counting was used to analyze the fractions of the isolated 149Pm from 147Nd. Solvent pH was determined to be the dominant factor in obtaining a good separation of lanthanides by HPLC.