PHYSICOCHEMICAL CHARACTERIZATION OF Portulaca oleracea L. SURFACE BY INVERSE GAS CHROMATOGRAPHY AT INFINITE DILUTION

Abstract

In this study, Portulaca oleracea L. plant, a low-cost biomass, was used as a stationary phase. The dispersive surface energy, acidic-basic character, enthalpy of adsorption, and Gibbs free energy of the surface of Portulaca oleracea L. were measured using a range of organic solvents with retention times in the infinite dilution. Using the Dorris-Gray (48.15 – 44.11 mJ/m²), Donnet-Park (46.55 – 42.59 mJ/m²), and Schultz (46.31 – 40.67 mJ/m²) methods, the dispersive surface free energy was determined to decrease linearly as temperature increased. For acid-base surface interactions, the specific enthalpy of adsorption and specific adsorption-free energy were found. Portulaca oleracea L.'s acidic and basic characteristics were calculated with the numbers of organic solvent donors and acceptors. According to the measured values and characteristics, Portulaca oleracea L. has an acidic character (K_D/K_A = 0.21).