Separation of 68Ga from 68Ge using a macroporous organic polymer containing N-methylglucamine groups

Gallium-68 (Ga-68) is a important positron-emitting radionuclide available for positron emission tomography. Since the Ga-68 is prepared by decay of germanium-68 (Ge-68) having a long half-life, separation of Ga-68 from Ge-68 is essential for the utilization of Ga-68. In this study, a macroporous styrene-divinylbenzene copolymer containing N-methylglucamine groups (R-MGlu) was selected as an adsorbent for Ge-68. This resin effectively and rapidly adsorbed Ge-68 above pH 5. By a batch method, 0.1 mol l(-1) trisodium citrate eluted over 90% of Ga-68 built up in the resin by decay of Ge-68 on the resin, although distilled water did not elute the Ga-68. A solution of ethlylenediaminetetraacetic acid or desferroxamine at a lower concentration also desorbed the Ga-68 in higher yield. These results indicated that Ga-68 was eluted by the formation of a complex with a suitable ligand. When 0.1 mol l(-1) sodium citrate was used as the eluting agent by a column method, most of the Ga-68 on the R-MGlu was recovered using 0.1 mol l(-1) sodium citrate, while the Ge-68 leakage was less than 0.0004% of the Ge-68 adsorbed on R-MGlu. (C) 2002 Elsevier Science B.V. All rights reserved.