Adsorption coefficient (K_oc) and HPCL retention factors of aromatic hydrocarbons

The determination of soil adsorption coefficients (K_oc) via HPLC capacity factors (k') has been studied, including the effect of column type and mobile phase composition on the correlation between log K_oc and log k'. Values of K_oc correlate well with the ethylsilica column capacity factors, and it is suggested this mildly hydrophobic phase is a better phase for prediction of the sorption of nonionic chemicals onto soil or sediment than either octadecyl- or phenylsilica phases, or partition into n-octanol. By using log k'_w a theoretical capacity factor has been obtained by extrapolation of retention data in a binary solvent system to pure aqueous eluent; the correlation between log K_oc and log k'_w is better than using log k'.