Lutetium-177 (177Lu) is a very promising radioisotope in nuclear medicine because of its beneficial decay regime (t1/2 = 6.6 days, Ebeta max = 497 keV). 177Lu radiopharmaceuticals can be applied for diagnosis (gamma emission) and treatment (beta minus emission) of tumors and metastases. A 177Lu-based radiopharmaceutical is already commercially available as 177Lu:DOTA-TATE complex (Lutathera®) for the treatment of neuroendocrine tumors. 177Lu is efficiently produced in a nuclear reactor via neutron irradiation of a highly enriched 176Yb target material, i.e. 176Yb(n, gamma)177Yb. Subsequent beta minus decay of 177Yb delivers the intended 177Lu isotope. However, the irradiated material will still mainly consist of 176Yb and 177Lu is only present in low concentrations. Therefore, 177Lu must be isolated from the target material before it can be used in radiopharmaceuticals. Leftover 176Yb can be re-used as target material for 177Lu production. However, efficient separation of Lu from Yb is challenging because the two neighboring lanthanides have very similar chemical properties.