A chromatograpluc techmque usmg radlotracer gases has been used to determine pure gas Isotherms and gas mtxture adsorptlon equdlbna over the entue concentration range The ethaneethylene-Molecular Sieve Type 13X and pure carbon monoxide-Molecular Sieve Type 5A systems were stud& The data obtamed by tlus dynamic techmque are shown to be m agreement with data obtamed previously by a static (volumetnc) method The chromatographc method IS much more efficient for obtammg mixture data and IS conslderably easier to adapt to wder pressure and temperature ranges than static methods lNTRODWTlON In recent years the demand for accurate, multlcomponent, gas-sohd adsorptlon equdrbrmm data has lead to mvestlgatlon of dynanuc methods mcorporatmg chromatographlc charactenstrcs for obtammg such data Compared to the more famlhar static methods, such techniques have the advantages of stmphclty, rapldlty m producing data, and easy adaptabihty to different temperature and pressure ranges Early chromatographlc te-chmques attempted to use the shape of the adsorption column response to a aven input to determine the adsorption isotherm More recent methods use the retention volume of an injected pulse as the measured parameter At first these mvolved only the mjectlon of a small sample of gas of shghtly daerent concentration than the tamer stream-a concentration-pulse The concentration-pulse techmque has been discussed m the literature by a number of authors mcludmg Stalkup and Deans[l], Stalkup and Kobayashi[t], Helfferlch[3], Peterson and Helfferlch [4], and Van der Vhst and Van der Mel]den[5] 'I&s method has been successfully apphed only to nearly-hnear isotherms (or the lmear remon thereof) so It IS restncted to a few special cases or to the very ddute portion of the isotherm Chromatographlc theory has been extended to cover the entue concentration range, even for systems with nonlinear isotherms This has been accomphshed by modeling the flow of a pulse of disSmgumhable molecules (normally radioactive isotopes of a component of the tamer gas) through the system Thus approach 1s known as the tracer-pulse techmque We this method has been used m a number of studies [3, &9] It 1s still best described as bemg m the developmental stage If the accuracy of the techmque can be venfied and the prob-