Some observations on the production and quality control of radioisotope 18F

18F is produced by neutron irradiation of lithium carbonate and is separated by dissolving the material in acid and distilling the hydrogen fluoride solution. The yield is better than 80%, radioactive impurities less than 1% and the residual tritium content is less than 0.1 μCi. Pure lithium carbonate (6Li content greater than 50%) was irradiated in a standard aluminium isotope can, for 1 hour at the fast transfer system (large rabbit) of the UTR-300 reactor of the Scottish Universities Research and Reactor Centre, East Kilbride, Scotland, in a neutron flux approximately 3.8x1012 n cm-2s-1. (F.Gy.)