[en] Fluorine contamination on and below the surface of zircaloy has been studied by means of proton irradiation using a Van de Graaff accelerator and the detection of prompt gamma radiation from the ¹⁹F (p, αγ) ¹⁶O reaction. Formulae for deriving depth distributions of impurities from the measured counting rates have been derived. The influence of energy straggling on the depth resolution has been studied. Both the total amount and the depth distribution have been measured in samples, which have undergone different treatments. Because of the high yield from the reaction used, a quantity of fluorine less than 0. 01 μg/cm² can be detected by this method