ADSORPTION-ISOTHERMS AND OVERLOADED ELUTION PROFILES OF PHENYL-N-ALKANES ON POROUS CARBON IN LIQUID-CHROMATOGRAPHY

The adsorption isotherms of phenyltridecane, phenylundecane, phenyldecane, and phenyloctane between acetonitrile and graphitized carbon have been measured by frontal analysis. Like the isotherm of phenyldodecane previously reported, all of these isotherms exhibit two inflection points and can be empirically accounted for by the sum of a quadratic and a Langmuir term. The elution profiles of large size samples of these hydrocarbons are calculated from the experimental isotherms, using the equilibrium-dispersive model of chromatography. In spite of the complexity of the profiles, the results of the calculations are in excellent agreement with the experimental band profiles.