The Elution characteristics of alpha-emitting impurities from Molybdenum-99/Technetium-99 m chromatographic generators

Abstract

Technetium-99 m generators produced from fission-based 99Mo may be contaminated with α-emitting impurities formed during irradiation of the uranium target material; these α contaminants may be partly extracted during the elution cycles of the generators. Because of the radiotoxic hazards associated with α impurities the British and U.S. Pharmacopoeias (1.2) prescribe strict limits for the allowable levels if gross α contaminants in 99 m Tc eluates derived from this source. As most commercially available 99Mo/ 99 m Tc generators consist of a small chromatographic column containing a solid stationary phase, (3–5) the elution behaviour of α contaminants from the stationary phase material is important in establishing a comprehensive quality assurance regime for routinely monitoring these impurities in the eluates. This note describes the desorption behaviour of radioactive neptunium, uranium and plutonium from alumina and serium-coated alumina stationary phase materials using an isotonic saline eluant.