DETERMINATION OF THE SOLUBILITY PARAMETER OF SOYBEAN OIL BY INVERSE GAS-CHROMATOGRAPHY

The solubility parameter of soybean oil, delta(2), has been determined by the technique of inverse gas chromatography (IGC). Using soybean ail as the stationary phase, solute retention volumes were precisely determined as a function of temperature using 22 solute probes of varying solubility parameter (delta(1)). Solvent (oil)-solute interaction parameters, chi, were also calculated from the solute retention data and indicate complete miscibility of the solute probes with the soybean oil at conditions of infinite dilution. The chi values and their dependence on temperature were used to compute delta(2) at 59, 79, 101, and 123 degrees C. Over this temperature interval, the delta(2) decreased from 7.9 to 6.9 cal(1/2)/cm(3/2) with decreasing temperature, a trend consistent with the loss of cohesional energy density in the liquid soybean oil.