Chemical properties
Sm-153 is a radiolanthanide, usually in trivalent state. It can be radiolabelled with macrocyclic chelators, in particular DOTA. The ionic radius is 95.8 pm.
Nuclear properties
Sm-153 decays by β- decay with a half-life of 1.9285(2) days to stable Eu-153. It emits a low to medium energy β- spectrum with 225 keV average energy and 808 keV maximum energy. In addition to β- emission it shows ample emission of low energy conversion and Auger electrons , thus emitting in total about 2.34 electrons (with energies above 4 keV) per decay.
Moreover, Sm-153 emits γ-rays at 103 keV (29.14%) suitable for SPECT imaging.
The mean electron energy emitted per decay is 265 keV, the mean photon energy per decay is 62 keV .
Production
Sm-153 is produced by thermal neutron irradiation of enriched Sm-152 oxide targets in the BR2 reactor at SCK CEN. The produced carrier-added Sm-153 is then mass separated at the MEDICIS facility at CERN. Thus, Sm-153 with high specific activity is obtained .
Distribution
A final radiochemical separation is performed at SCK CEN (Mol, Belgium). Activity will be shipped from there to the users in form of SmCl3 solution, ready for labelling of e.g. DOTA-compounds.
Examples of use
| Parameter | Specifications |
|---|---|
| Production route | Sm-152(n,γ)Sm-153 |
| Daughter | Decays to stable Eu-153: 100% β- |
| Half-life | 1.93 d |
| Processing | Off-line mass separation (CERN-MEDICIS) + 3-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 or solid deposit |
| Chemical Form | In 0.05 M HCl (evaporation to dryness is also possible) |
| Radioactive Concentration (gamma spectrometry) | > 50 MBq/ml |
| Appearance | Clear colourless solution |
| Radionuclide identification (gamma spectrometry) | 70 keV, 97 keV and 103 keV gamma lines present |
| Radionuclidic Purity (gamma spectrometry) | >99.99% |
| Chemical purity (ICP-OES) | n.a. |
| Molar activity (ICP-OES) | 280 GBq/µmol Sm at time of mass separation (>11% of theoretical maximum) |
| Apparent Molar Activity | Labelling up to 50 MBq/nmol p-SCN-Bn-DOTA and DOTATATE |
| Microbiological quality | n.a. |
| Bacterial endotoxin | n.a. |
| pH (pH strips) | 1-2 |
| Additional information | |
| Activity available | Up to 150 MBq on demand (availability CERN-MEDICIS + BR2 reactor cycle) |
| Activity limit for UN2910 (excepted package) shipment | 0.6 GBq in dry state or 60 MBq in liquid form |
| Other information | Labelling up to 50 MBq/nmol p-SCN-Bn-DOTA and DOTATATE |