Application of the characteristic root index model to the estimation of N-octanol/water partition coefficients. polychlorinated biphenyls

The ability of the Characteristic Root Index (CRI) to predict the n-octanol/water partition coefficients (Kow) of polychlorinated biphenyls (PCBs) has been demonstrated. The CRI for 58 congeners were calculated from the roots of the characteristic polynomial obtained from a square matrix comprising all possible orders of valence connectivity index — except zero order — for a congener as the entry. The correlation proposed for the estimation of Kow of PCBs based on the CRI model contains only one variable and predicts log Kow with high regression coefficient (r=0.998) and may be regarded satisfactory for environmental applications.