The valence distribution of radiophosphorus in potassium and lithium chlorides: The dissolution step

The effect of the presence or absence of carriers in the disolution medium on the valence distribution of radiophosphorus produced by the reaction 35 Cl(n, α)32P has been studied using both A.R. KCL powder and zone refined single crystals of KCL. The results are consistent with the hypothesis that the carriers, especially the P(I) (hypophosphite), act as protective agents for the recoil species during dissolution. Any changes in the valence distribution which occur on disolution always seem to be oxidative, resulting in an increase in the P(V) (phosphate) and decrease in P(I) fractions. The presence or absence of carriers has little effect when ammonium acetate buffer is used as the dissolution medium. Since this solution also gives the lowest P(V) fraction, this is evidence that there is little change in the valence distribution of radiophosphorus on dissolution, and that the distribution in this case therefore represents the valence distribution actually present in the solid immediately prior to dissolution. Irradiated LiCl was dissolved in dry ethanol and aqueous carrier solutions added subsequently. When completely dehydrated, LiCl was used, about half of the radiophosphorus appeared as organic species. Two organic compounds were separated by thin layer chromatography, but no further identification was made. In the other sample (dry A.R.LiCl) no organic species was formed and most of the radiophosphorus appeared in the P(V) fraction. (orig.)