Estimation of amorphous organic carbon/water partition coefficients, subcooled aqueous solubilities, and n-octanol/water distribution coefficients of alkylbenzenes and polycyclic aromatic hydrocarbons

The aim of this work was to derive a relation between the number of specific carbon atoms in alkylbenzenes and PAHs and the average log Koc for linear partitioning between amorphous organic carbon in soils and sediments and water. The relation between the number of specific carbon atoms and n-octanol/water partitioning and subcooled aqueous solubility was sought first, as the number of data for partitioning into amorphous organic carbon was relatively sparse. It turned out that linear partitioning into amorphous organic carbon could be described by a linear relation based on the number of aromatic carbons, the number of alkyl carbons and the number of alicyclic carbons in the same way as for n-octanol/water partitioning and subcooled liquid aqueous solubility. From the linear regressions for linear partitioning into the various amorphous organic carbons, an average intercept for the linear partitioning regression equation was derived to represent average organic carbon in soils and sediments.