Nam-Soo Lee

Separation of magnesium isotopes by chemical exchange with manganese (IV) oxide

Separation of magnesium isotopes was investigated by chemical ion exchange with manganese (IV) oxide using an elution chromatographic technique. The capacity of manganese (IV) oxide ion exchanger was 0.5 meq/g. The heavier isotopes of magnesium were concentrated in the manganese oxide phase, while the lighter isotopes were enriched in the solution phase. The glass ion exchange column used in our experiment was 35 cm long with inner diameter of 0.2 cm, and 1.0 M CH3COONH4 solution was used as an eluent. The single stage separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assays. The separation factors of 24Mg2+-25Mg2+, 24Mg2+-26Mg2+, and 25Mg2+-26Mg2+ were 1.008, 1.014, and 1.006, respectively.

Synthesis of AM15C5 bonded Merrifield peptide resin and its separating properties

Abstract A 2-aminomethyl-15-crown-5 (AM15C5) bonded Merrifield peptide resin was synthesized. The capacity of this crown ion exchanger was 2.25 meq/g of dry resin. The heavier isotopes of magnesium were enriched in the solution phase, while the lighter isotopes were enriched in the resin phase. The hydration and isotope mass effects dominated over those of the complexation and properties of the exchanger. The separation factors of 24Mg2+/25Mg2+, 24Mg2+/26Mg2+, and 25Mg2+/26Mg2+ isotope pair fractionations were 1.0012, 1.0023, and 1.0011, respectively.