Supercooled liquid vapour pressures and related thermodynamic properties of polycyclic aromatic hydrocarbons determined by gas chromatography

Abstract A gas chromatographic method using Kovats retention indices has been applied to determine the liquid vapour pressure ( P i ), enthalpy of vaporization (Δ H i ) and difference in heat capacity between gas and liquid phase (Δ C i ) for a group of polycyclic aromatic hydrocarbons (PAHs). This group consists of 19 unsubstituted, methylated and sulphur containing PAHs. Differences in log  P i of −0.04 to +0.99 log units at 298.15 K were observed between experimental values and data from effusion and gas saturation studies. These differences in log  P i have been fitted with multilinear regression resulting in a compound and temperature dependent correction. Over a temperature range from 273.15 to 423.15 K, differences in corrected log  P i of a training set (−0.07 to +0.03 log units) and a validation set (−0.17 to 0.19 log units) were within calculated error ranges. The corrected vapour pressures also showed a good agreement with other GC determined vapour pressures (average −0.09 log units).