Gas-Solid Chromatographic Separation of Hydrocarbons of High Molecular Weight

Abstract

THE deactivation of highly active polar sites on activated alumina with water to give a satisfactory column packing for the gas chromatographic separation of C₁–C₅ hydrocarbons at room temperature has been reported¹. An extension of this work has shown that alumina can be similarly deactivated with inorganic bases and salts added in aqueous solution, the water being removed by subsequent heat treatment. At low degrees of deactivation, retention volumes for aromatic hydrocarbons can be varied relative to aliphatic hydrocarbons according to the extent of deactivation. However, the amount of sample required (∼100 µgm.) to obtain a response from a flame-ionization detector suggests that considerable irreversible adsorption takes place. The most promising application appears to be at the highest degrees of deactivation (lowest activity-levels, when irreversible adsorption is much reduced) for the separation of high-molecular weight hydrocarbons.