Chemical properties
Yb-175 is a radiolanthanide, most often in trivalent state and chemically very similar to lutetium. The ionic radius of Yb3+ is 87 pm, i.e. differing by less than 1% from that of Lu3+, which explains that macrocyclic chelators suitable for Lu-177 can be directly employed for Yb-175 too, in particular DOTA. The ionic radius is 86.8 pm.
Nuclear properties
Yb-175 decays by β- emission with a half-life of 4.1615(30) days to stable Lu-175. In addition to low-energy β- emission (mean energy 113 keV, maximum energy 470 keV) it shows emission of low energy conversion and Auger electrons , thus emitting in total about 1.17 electrons (with energies above 6 keV) per decay.
Moreover Yb-175 emits γ-rays- and X-rays, notably 396.3 keV (13.2(3)%) and 282.5 keV (6.13(8)%). These make Yb-175 suitable for SPECT imaging with high energy collimators.
The mean electron energy emitted per decay is 120 keV, the mean photon energy per decay is 80 keV.
Production
Yb-175 is produced by thermal neutron irradiation of enriched Yb-174 oxide targets in the high flux reactors of the production facilities: RHF at ILL or BR2 at SCK CEN.
Distribution
Off-line mass separation is performed at the production facility MEDICIS (CERN, Geneva, Switzerland). Activity will be shipped from there to the users in form of YbCl3 solution or in solid form, implanted into an Al, Zn or NaCl layer.
| Parameter | Specifications |
|---|---|
| Production route | Yb-174(n,γ)Yb-175 |
| Daughter | Decays to stable Lu-175: 100% β- |
| Half-life | 4.16 d |
| Processing | Off-line mass separation + 2-step column separation |
| Primary Container | 2.5 mL borosilicate glass V-vial with silicon rubber screw cap |
| Product Grade | n.c.a. (but not in theoretical molar activity) |
| Physical Form | Liquid |
| Chemical Form | In 0.05 M HCl |
| Radioactive Concentration (gamma spectrometry) | n.a. |
| Appearance | Clear solution |
| Radionuclide identification (gamma spectrometry) | 283 keV and 396 keV gamma lines present |
| Radionuclidic Purity (gamma spectrometry) | >99.9% |
| Chemical purity (ICP-OES) | n.a. |
| Molar activity (ICP-OES) | n.a. |
| Apparent Molar Activity | n.a. |
| Microbiological quality | n.a. |
| Bacterial endotoxin | n.a. |
| pH (pH strips) | n.a. |
| Additional information | |
| Activity available | Up to 200 MBq few times per year (planning in advance), depends on reactor and MEDICIS schedule |
| Activity limit for UN2910 (excepted package) shipment | 0.9 GBq in dry state or 90 MBq in liquid form |
| Other information | Research grade implanted in Al, Zn or NaCl layer on gold foil also possible |