Au-199 is usually in trivalent state.
Au-199 decays by β- emission with a half-life of 3.139(7) days to stable Hg-199. It emits a low energy β- spectrum with 82 keV average energy and 452 keV maximum energy. In addition to β- emission it emits low energy conversion and Auger electrons , thus emitting in total about 1.42 electrons (with energies above 7 keV) per decay. Hence, Au-199 is a β--emitter with half-life similar to Sc-47, but low energy electron spectrum, similar to Er-169 or Tb-161.
Moreover Au-199 emits γ-rays at 158.4 keV (40%) and 208.2 keV (8.72%), making it suitable for SPECT-imaging (possibly requiring high-energy collimators in presence of Au-198 admixture).
The mean electron energy emitted per decay is 112 keV, the mean photon energy per decay is 95 keV .
Carrier-added Au-199 is produced by double neutron capture on Au-197 targets in the high flux reactor RHF at ILL. This production route leads to co-production of Au-198.
Irradiated targets are dissolved and separations are performed at Hevesy Laboratory (DTU, Risø, Denmark). Activity will be shipped from there to the users in form of AuCl3 solution.
Examples of use
|Daughter||Decays to stable Hg-199: 100% β-|
|Primary Container||2.5 mL borosilicate glass V-vial with silicon rubber screw cap|
|Physical Form||Liquid or dried deposit|
|Chemical Form||In 0.05 M HCl|
|Radioactive Concentration (gamma spectrometry)||n.a.|
|Radionuclide identification (gamma spectrometry)||158 keV and 208 keV gamma lines present|
|Radionuclidic Purity (gamma spectrometry)||80-90% (also 10-20% Au-198)|
|Chemical purity (ICP-OES)||n.a.|
|Molar activity (ICP-OES)||About 1 GBq/µmol (0.06% of theoretical maximum)|
|Apparent Molar Activity||n.a.|
|Microbiological quality||Bioburden and endotoxin burden can be analysed post release, upon request|
|Bacterial endotoxin||Bioburden and endotoxin burden can be analysed post release, upon request|
|pH (pH strips)||n.a.|
|Activity available||Few GBq few times per year (planning in advance), depends on reactor schedule|
|Activity limit for UN2910 (excepted package) shipment||0.6 GBq in dry state or 60 MBq in liquid form (combined Au-199 and Au-198 activity)|
|Other information||Au-198 : half-life 2.69 days, medium energy β-decay and emission of 412 keV (95.62%) γ-rays. For future needs the alternative production of n.c.a. Au-199 (higher molar activity and free of Au-198 admixture) could be considered|