S.G. Dolley

Isolation of Cu radionuclides with dithizone impregnated XAD-8

Abstract A novel separation method for Cu radionuclides from proton bombardment of natZn is presented. A solid phase extraction procedure using a modified dithizone (diphenylthiocarbazone) XAD-8 chelating resin was used for the purification of the Cu radionuclides from up to 5 g of natZn and other radionuclides. More than 95% of the Cu radionuclides was recovered.

The use of selective volatization in the separation of 68Ge from irradiated Ga targets

Cyclotron-produced (68)Ge can be separated from its Ga target material by dissolving the target in aqua regia and collecting the volatile (68)Ge in a solution containing 1.0M NaOH and 2% Na₂SO₃. The solution is then acidified with HF before being loaded onto a column containing AG MP-1 anion exchange resin. The column is rinsed with dilute HF to remove any remaining impurities, before eluting the desired product with 0.1M HCl. A radiochemically pure product is obtained.

Production of 111In from an In/In2O3 target

Summary A method was developed to produce 111In from an In/In2O3 target, whereby the parent 111Sn was separated from the target material by means of ion exchange, using AG1-X4 and AG MP-1 anion exchange resins. The chemical separation had to be performed as quickly as possible, to ensure the highest possible yield of the final product (111Sn has a half-life of 35.3 minutes). The 111Sn is left on the resin to decay to 111In, which is then eluted from the column. This method ensures that impurities in the final product are kept to a minimum.

Concurrent spectrometry of annihilation radiation and characteristic gamma-rays for activity assessment of selected positron emitters

A method is described to determine the activity of non-pure positron emitters in a radionuclide production environment by assessing the 511keV annihilation radiation concurrently with selected γ-lines, using a single High-Purity Germanium (HPGe) detector. Liquid sources of 22Na, 52Fe, 52mMn, 61Cu, 64Cu, 65Zn, 66Ga, 68Ga, 82Rb, 88Y, 89Zr and 132Cs were prepared specifically for this study. Acrylic absorbers surrounding the sources ensured that the emitted β+-particles could not escape and annihilate away from the source region. The absorber thickness was matched to the maximum β+ energy for each radionuclide. The effect on the 511keV detection efficiency by the non-homogeneous distribution of annihilation sites inside the source and absorber materials was investigated by means of Monte Carlo simulations. It was found that no self-absorption corrections other than those implicit to the detector calibration procedure needed to be applied. The medically important radionuclide, 64Cu, is of particular interest as its strongest characteristic γ-ray has an intensity of less than 0.5%. In spite of the weakness of its emission intensity, the 1346keV γ-line is shown to be suitable for quantifying the 64Cu production yield after chemical separation from the target matrix has been performed.

Large discrepancies in the excitation function data of the 68Zn(p, x)64Cu reaction: A possible explanation

The excitation function of the 68Zn(p, x)64Cu reaction was investigated in an attempt to clarify a serious discrepancy in the recently published data. New measurements based on both a weak γ-line of 1345.8 keV (0.47%) as well as the 511 keV annihilation radiation were performed after radiochemically separating the Cu from the Zn target matrix. In the case of the 511 keV measurements, the method of decay-curve analysis was employed as the annihilation radiation is not specific for a particular radionuclide. The results from the two methods were found to be in excellent agreement. Simulations were also performed to test the method of 511 keV decay-curve analysis for the effects of possible intruder contaminants.