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