Application of a collidinium molybdoarsenate ion-exchange column to the separation of thallium(I)

Abstract

Collidinium 12-molybdoarsenate, prepared by the reaction of sodium 12-molybdoarsenate and collidinium nitrate, is stable in water, acids and salt solutions. Distribution coefficients have been determined for various metal ions in aqueous media at pH 3–4. The compound is highly selective towards thallium(I) and can be used for its separation from other cations. Binary separations of microgram amounts of thallium(I) from large amounts of other metal ions have been carried out. In ammonium nitrate media a large separation factor is obtained for the separation of thallium(I) from a caesium and rubidium ions, which has not so far been reported with other ion exchangers.