E. Dadachova, S. Mirzadeh, R. Lambrecht
Dec 1, 1994
Citations
2
Influential Citations
40
Citations
Journal
Analytical Chemistry
Abstract
Holmium-166 ([sup 166]Ho, t[sub 1/2] = 26.4 h) is utilized in radiotherapeutic applications such as radioimmunospecific pharmaceuticals, bone marrow ablation, and radiation synovectomy. High specific activity [sup 166]Ho can be obtained from the decay of dysprosium-166 ([sup 166]Dy, t[sub 1/2] = 81.5 h). Dysprosium-166 is produced by the [sup 164]Dy[n,[gamma]][sup 165]Dy[n,[gamma]][sup 166]Dy reaction in a nuclear reactor. The applicability of reversed phase ion-exchange chromatographic methods was demonstrated for the separation of carrier-free [sup 166]Ho from milligram quantities of [sup 164]Dy[sub 2]O[sub 3] irradiated targets. An efficient and quantitative separation was achieved utilizing a metal-free HPLC system with Dowex AG 50WX12 or Aminex-A5 cation exchangers and [alpha]-hydroxy-isobutyric acid ([alpha]-HIBA) as the eluent (0.085 M, pH = 4.3 adjusted with NH[sub 4]OH). The Aminex-A5 column gave a separation factor of approximately 10[sup 3] between Ho and Dy. Subsequent to the acidic destruction of the Ho-HIBA complex, Ho[sup 3+] was further purified on a small cation-exchange column from acidic chloride solutions. The separation was achieved within 2 h, with a 95% overall radiochemical yield for carrier-free [sup 166]Ho with a Dy breakthrough of < 0.1%. 32 refs., 7 figs., 1 tab.