Tritium retention measurements have been carried out on samples of LiAlO2, Li2SiO3 and Li2O of various density, irradiation time and temperature. The reported results were obtained by dissolution of the samples in concentrated KOH and by heating the samples up to 900 °C under a helium flow. Both techniques are described. The results are compared with the in-situ tritium release experiments carried out in the High Flux Reactor at Petten, The Netherlands. The in-situ release and post-irradiation retention measurements are in good agreement. Tritium inventory depends predominantly on temperature and density. For the materials with a density of approximately 80% TD and irradiated at about 600 °C tritium inventories of ≪1 wppm can be achieved. Higher densities and lower temperatures result in inventories > 1 wppm.