The inverse beta decay is the most important reaction for registration of an electronic antineutrino. v˜e+p=e+n↗n+p→d+γ(2.2MeV)↘n+157GD+γ(8MeV) The detector of electronic antineutrinos consists of a target and a gamma-ray detector. Sorbent C100 with the applied gadolinium is supposed to be used as a target for the detector to register the products of reaction ṽ _e + p= e ⁺ + n. According to the Boyd model [1], the sorption on ion-exchange resins is a complicated and multistage process that includes mechanisms of external (film) diffusion and internal (gel) diffusion. The mechanism of chemical reaction also influences the sorption process. Diffusion mechanisms are sequential stages of the sorption process, so that the slowest of them is the limiting stage of the process. The sorption kinetics was examined by the finite volume method. The main purpose was to reveal the limiting stage in each phase of the sorption process [2] in system Gd ³⁺ –C100 in H ⁺ form. It was necessary to find out how the acid concentration and temperature influence the sorbent sorption properties.