Separation of magnesium isotopes by chemical exchange with a polymer-bound azacrown compound

The chromatographic separation of magnesium isotopes was investigated by chemical exchange with the recently synthesized 1-oxa-4,7,10,13-tetraazacyclopentadecane-4,7,10,13-tetramerrifield peptide resin [N4O·4M]. The capacity of the novel N4O-4 Merrifield ion exchanger was 1.0 meq/g dry resin. The heavier isotope26Mg concentrated in the resin phase, while the lighter isotopes24Mg, and25Mg are enriched in the fluid phase. The maximum separation factors α, for25Mg−26Mg and24Mg−26Mg were found to be 1.048 and 1.022, respectively, at 20.0±0.02 °C with 2.0 M ammonium chloride solution as an eluent.