Determination of fluorine adsorbed on inorganic ion exchanger was studied by activation analysis using19F(γ,n)18F and19F(n, α)16N reactions. Hydrated tin dioxide and activated alumina were used as inorganic ion exchangers. After adsorption of fluorine on the column, the exchanger was irradiated by the linear electron accelerator and252Cf fission neutron source, and the content of fluorine was determined by reactivation. The determination of oxygen in silicon single crystal was studied by the reactivation analysis.