Inverse gas chromatographic method for determining sorption of water and ethanol on sweet potato

Abstract

Inverse Gas Chromatographic Method (IGC) was used to determine the vapor sorption of water and ethanol on sweet potato particles in the temperature range of 60-150°C. From the Chromatographic retention data it was possible to calculate the separation factors for the two solutes and to obtain values for thermodynamic parameters such as Gibb's free energy (ΔGS) and the enthalpy (ΔHs) of adsorption of water and ethanol on to the sweet potato adsorbent. The results showed that sweet potato adsorbed water to a greater extent than ethanol at all temperatures, and the low temperature is propitious to adsorption. The ΔHs values obtained for water were significantly higher than those for ethanol, indicating stronger water/substrate interactions. The scanning electron microscope(SEM) was used to observe the surface properties of the sweet potato.