Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

Dimensionless Henry s law constants (air/water partition coefficient Kaw) of four volatile organic compounds (VOCs), namely, methyl tert-butyl ether, vinyl acetate, dimethyl carbonate, and diethyl carbonate, are reported. Applying headspace solid-phase microextraction (HS-SPME) in combination with gas chromatographic analysis, whose response was calibrated by the use of standard gas mixtures, Kaw values (0.001 less than Kaw less than 0.1) were determined in the temperature range of (10 to 45) deg C. Replicated measurements showed a good repeatability (average relative standard deviation 2.5 %, n = 144). The results were checked through additional Kaw measurements carried out using the inert gas stripping (IGS) technique at 25 deg C, receiving intermethod deviations less than 5 %. Furthermore, approximate values of hydration enthalpies ?Hhyd and hydration entropies ?Shyd for the four VOCs were derived from linear van t Hoff fits of the Kaw(T) data, demonstrating an enthalpy-driven partition process.