Gas absorption and desorption into liquids are dynamic phenomena that can occur in process engineering. Consequences could be dramatic if these changes are sudden and uncontrolled. Thus, prediction is expected to keep them under control, but it requires some preliminary work to know more about the diffusion coefficient and Henry's law coefficient for accurate modeling. Transient behavior is even trickier and shall be studied. In this work, a pure jet fuel fluid is used as a solvent with pure nitrogen (N-2) to study its solubility. As N-2 is the main component of atmospheric air, this work is also related to the natural absorption of N-2 by the jet fuel, which is related to the aging and alteration of fuel when stored at ambient conditions. An experimental test bench has been developed specifically to physically and chemically quantify the gas absorption. Pressures up to 50 bar are considered over long pressurization time (up to 24 h) to study saturation conditions. Sudden pressurization and depressurization steps are achieved for unsteady investigations. The effects of the contact surface between liquid and gas, the penetration depth of gas into fluid, the pressure level, and the time of pressurization were observed. The contact surface is demonstrated to play a multiplier role on gas absorption, while the pressure and the depth of fluid strictly transmit their own evolution in a proportional way on the solubility phenomenon. An analytical model is developed, and values of Henry's law coefficient (510 atm) and of diffusion coefficient (3.10-8 m(2) s(-1)) are determined experimentally for making this analytical model to be predictable for larger and realistic configuration. An example of application is provided.