Limitations of the Koc Concept Inferred from 1-Methylnaphthalene Sorption on Organic Coated Minerals

Several authors have studied sorption of nonpolar organics on soils, sediments, and aquifer material (1,2,3). On surface soils with organic carbon (OC) concentrations greater than 0.1%, the sorption was controlled by the fraction of OC in the sorbent. The sorption coefficient (K) for a compound on an unknown sorbent could be predicted from the sorbent organic content using the relationship K_oc = K/f_OC where K_oc is the OC normalized sorption coefficient, K the sorption coefficient, and f_OC the fraction organic carbon content.