Adsorption and isotopic fractionation of Xe

Abstract

We give a theoretical description of the mechanisms of isotopic fractionation arising during adsorption of noble gases in a Henry's Law pressure regime. We also present experimental data on the isotopic composition of Xe adsorbed on activated charcoal in the temperature range 220°K to 350°K. Both theoretical considerations and the experimental data indicate that equilibrium adsorption does not significantly alter the isotopic structure of adsorbed noble gases. Therefore, if adsorption is responsible for the elemental noble gas pattern in meteorites and the earth, the heavy noble gas isotopic fractionation between them must have been produced prior to and by a different process than equilibrium adsorption. © 1986.