Chemical properties
Pd-103 belongs to the platinum group elements and is either in metallic form or divalent in compounds. Palladium in metallic form is difficult to dissolve, but aqua regia can do it and will yield a strong orange-red solution.
Nuclear properties
Pd-103 decays by electron capture decay with a half-life of 17.0 days to isomeric Rh-103m that decays in turn with 56.11 min half-life to the stable ground state of Rh-103.
Pd-103 in equilibrium with its daughter Rh-103m emits X-rays, notably Kα at ≈20 keV (64.9(14)%) and Kβ at ≈23 keV (12.0(2) %). Pd-103/Rh-103m emit only very weak γ-rays, namely at 39.7 keV (0.07%) REF and 357.5 keV (0.022%) plus still weaker ones REF
The mean photon energy per Pd-103 decay in equilibrium with Rh-103m is 16 keV and the mean electron energy emitted per decay is 40 keV. Most of these electrons are short-range Auger and conversion electrons with <0.3 µm, <7 µm and <27 µm range respectively.
The mean photon energy per Rh-103m decay alone is 1.7 keV and the mean electron energy emitted per decay is 38 keV. All its electrons are short-range Auger and conversion electrons with <0.3 µm, <7 µm and <27 µm range respectively.
Pd-103 is mainly used in brachytherapy sources exploiting its X-ray emission, while Rh-103m has been proposed as therapeutic Auger electron emitter. Due to its very low photon-to-electron ratio, Rh-103m has been recommended for targeted therapy of small tumours REF.
Production
Carrier-added Pd-103 is produced by neutron irradiation of enriched Pd-102 targets at ILL. Non-carrier-added (n.c.a) Pd-103 is produced by proton irradiation of natural Rh targets at DTU. Dissolution and purification of both carrier-added and n.c.a. Pd-103 are performed at DTU.
Distribution
Activity will be shipped from DTU to the users in form of PdCl2 solution or dried.
Examples of use
| Parameter | Specifications |
|---|---|
| Production route | n.c.a.: Pd-102(n,γ)Pd-103 or c.a.:Rh-103(p,n)Pd-103 |
| Daughter | Decays by 100% EC, mainly to isomeric Rh-103m (56.1 min half-life) that decays to stable Rh-103g |
| Half-life | 17.0 d |
| Processing | 1-step ion exchange chromatography to remove Ag-111 impurities or 2-step extraction |
| Primary Container | 2.5 mL borosilicate glass V-vial with silicon rubber screw cap |
| Product Grade | Available in c.a. form (reactor produced) or n.c.a form (cyclotron produced) |
| Physical Form | Liquid |
| Chemical Form | Pd2+ ion in 0.1 M HCl solution (1-2 ml) |
| Radioactive Concentration (gamma spectrometry) | ~GBq/ml |
| Appearance | Clear colourless solution |
| Radionuclide identification (gamma spectrometry) | 40 keV gamma line and X-rays present |
| Radionuclidic Purity (gamma spectrometry) | >99.9% |
| Chemical purity (ICP-OES) | Metal impurities determined by ICP-OES for each batch of n.c.a. Pd-103. Typical 2 nmol Pd, 1 nmol Rh, 10 nmol Al, 4 nmol Fe, and 5 nmol Zn per batch (subject to revision). Equivalent numbers for c.a. to be determined. |
| Molar activity (ICP-OES) | Typically > 0.1 GBq/μmol Pd (c.a.) at End Of Chemistry (EOC) or > 100 GBq/μmol Pd (n.c.a.) at EOC (>35% of theoretical maximum (n.c.a.)) |
| Apparent Molar Activity | t.b.d. |
| 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) | Depends on chemical form |
| Additional information | |
| Activity available | Few GBq, few times per year (c.a.) and 200 MBq per batch (n.c.a.) |
| Activity limit for UN2910 (excepted package) shipment | 40 GBq in dry state or 4 GBq in liquid form |
| Other information |
