The main objective of this report was the understanding of the effect of higher pressures on the velocity of the gas-liquid interface. Experimental evidence (Le Romancer et al.) suggests that high-pressure gas injection results under certain conditions in a decrease of the rate of the interface motion, a result that may be due to gas dissolution and diffusion in the liquid phase. To explore this possibility, it was considered in this paper a simple 1-D model of this process as illustrated schematically in a figure. A liquid A, originally occupying a semi-infinite medium, is subject to evaporation and diffusion in a flowing gas B, the composition of which at the top of the medium (at z = 0) remains constant. Due to the possible high pressure in the gas, component B may solubilize and counter-diffuse in the liquid phase.