Purification of a 166mHo solution by successive high-performance liquid chromatography and gravitational chromatography for half-life determination

A methodology to purify a 166mHo solution has been developed by a combination of activity and mass concentration measurements in order to further determine the 166mHo half-life. The isobaric interference at m/q ≃ 166 requires Ho purification from non-natural Er with a high purification degree due to the large amount of Ho as opposed to Er. The Ho/Er separation was achieved using high-performance liquid chromatography on a semi-preparative column followed by purification on gravitational chromatography. The efficiency of the separation was evaluated after precise determination of the Er isotopic composition. The purification methodology enabled to separate Ho from Er. (author)