Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The vapor pressures and vaporization enthalpies of (-) alpha-bisabolol and (dl)-menthol, two GRAS chemicals (generally recognized as safe) are evaluated by correlation gas chromatography using a series of saturated primary alcohols as standards. Vaporization enthalpies of (96.6 +- 2.4) and (74.2 +- 2.8) kJ mol 1 and vapor pressures of p/Pa = (0.020 +- 0.003) and (4.5 +- 0.44) were evaluated at T = 298.15 K for (-) alpha-bisabolol and (dl)-menthol, respectively, and compared to literature values. The vapor pressures of both compounds from T = (298.15 to 500) K have been derived from correlations using vapor pressures of a series of 1-alkanols and corresponding gas chromatographic retention times at 10 K intervals. The results were fit to a second order polynomial. Calculated normal boiling temperatures of TB = (574.8 and 492.7) K are calculated for (-) alpha-bisabolol and (dl)-menthol, respectively. A normal boiling temperature of TB = (485.2, and 489.7) K has previously been reported for (dl)-menthol. Vapor pressures for both (l)-menthol and (dl)-menthol from a previous study and (dl)-menthol from this study are compared with literature values.