Radiochemical separation of no-carrier-added radioniobium from zirconiu targets for application of90Nb-labelled compounds

Abstract

SummaryThe radioisotope90Nb is a positron emitter with a relatively high positron branching of 51% and a rather low β+-energy ofEmean= 662 keVEmax= 1.5 MeV) with potential for application in positron emission tomography (PET). Its half-life of 14.6 h makes it especially promising for the quantitative investigation of biological processes with slow distribution kinetics. An advantageous production route of90Nb is thenatZr(p,n)90Nb process. To separate nca (no-carrier-added) radioniobium from macroscopic amounts of irradiated zirconium targets, an effective two step separation procedure was developed. A liquid-liquid extraction using N-benzoyl-N-phenylhydroxylamine (BPHA) in CHCl3was applied first to separate the bulk of the zirconium matrix with a Zr separation coefficient of about 104, followed by anion-exchange chromatography for high grade purification of nca radioniobium. A sufficiently high decontamination factor of > 2 × 107and an overall radiochemical yield of nca90Nb of about 70% was achieved within about 3 hours.