The macro separation of stable isotopes on ion-exchange columns

A review of the work carried out in the Ames Laboratory of the Atomic Energy Commission at Iowa State University, [U.S.A.], U.S.A..

Abstract

The methods of separating macro quantities of stable isotopes on cation exchange columns as developed at Iowa State University will be discussed, with particular emphasis on the ¹⁴N, ¹⁶N systems. The quantitative theory which permits such variables as the degree of separation, the quantities of chemicals required, and the amount of solution needed, to be calculated in advance, will be discussed in detail.

The theory is rather simple in principle, since it only requires a knowledge of material balance equations and a few experimental facts such as the capacity of the resin, the apparent equilibrium constants of the reactions which are taking place in the column and the exchange separation factors of the isotopes exchanging in the column. The theory is also applicable to anion-exchange columns for other isotopes.

Over one hundred grams of 99,7 % ¹⁵N were separated in the laboratory by these methods.