A rapid determination method of the air/water partition coefficient and its application

The air/water partition coefficient (Kaw) and Henryʹs constant (H) were measured by our own modified EPICS (Equilibrium Partitioning in Closed System) method, which uses two bubble columns. This method gives accurate Kaw data much more rapidly than other methods. In order to establish this method, the influence of airflow rate and the volume ratios of water in two columns to partition coefficient were carefully examined. Then we have measured Kaw for some n-alkanes, aromatic and chlorinated compounds. The experimental results of our modified EPICS method agreed very well with literature values. Besides the relationships between Kaw and molar volume, vapor pressure and water solubility were also analyzed.