Sc-47 is a rare earth, usually in trivalent state. It can be radiolabelled with macrocyclic chelators, in particular DOTA.The ionic radius is 74.5 pm.
Sc-47 decays by β- emission with a half-life of 3.3492(6) days to stable Ti-47. It emits a low energy β- spectrum with 162 keV average energy and 600 keV maximum energy. Emission of conversion and Auger electrons is negligible (<1%).
Moreover, Sc-47 emits γ-rays at 159.4 keV (68.3%) suitable for SPECT-imaging.
The mean electron energy emitted per decay is 162 keV, the mean photon energy per decay is 109 keV .
Sc-47 is produced indirectly by thermal neutron irradiation of enriched Ca-46 oxide or carbonate targets in the research reactors of the PRISMAP network: RHF at ILL, BR2 at SCK CEN and MARIA at NCBJ. The Ca-47 (T1/2=4.54 d) produced upon neutron capture decays to Sc-47 via β-minus decay and serves as a generator, allowing several subsequent elutions of Sc-47 . With respect to other production pathways of Sc-47, this production scheme provides optimum radionuclidic purity .
The radiochemical separations are performed at POLATOM (NCBJ, Otwock-Swierk, Poland). Activity will be shipped from there to the users in form of ScCl3 solution, ready for labelling of e.g. DOTA-compounds.
Examples of use
|Daughter||Decays to stable Ti-47: 100% β-|
|Processing||2-step column separation|
|Primary Container||2.5 mL borosilicate glass V-vial with silicon rubber screw cap|
|Chemical Form||In 0.05 M HCl or 4.85 M NaCl /0.13 M HCl|
|Radioactive Concentration (gamma spectrometry)||n.a.|
|Appearance||Clear colourless solution|
|Radionuclide identification (gamma spectrometry)||159 keV gamma line present|
|Radionuclidic Purity (gamma spectrometry)||> 99.95% (< 0.005% Sc-46)|
|Chemical purity (ICP-OES)||n.a.|
|Molar activity (ICP-OES)||n.a.|
|Apparent Molar Activity||Labelling up to 10-25 MBq/nmol DOTANOC (>96%) or ≈10 MBq/nmol DOTATATE (>95%)|
|pH (pH strips)||Depends on chemical form|
|Activity available||Up to 500 MBq few times per year (planning in advance), depends on reactor schedules|
|Activity limit for UN2910 (excepted package) shipment||0.7 GBq in dry state or 70 MBq in liquid form|