Isothermal capacity factors k on three gas chromatographic columns of different polarity were determined for chlorobenzenes (CBzs) and polychlorinated naphthalenes (PCNs). All possible multiple linear regressions of the logarithm of these capacity factors with previously reported temperature-dependent octanol-air partition coefficient (K-OA) values of selected CBzs and PCN congeners were performed to derive predictive relationships for the remaining congeners. A comparative evaluation of the regression coefficients and the standard error of the predicted K-OA values revealed that regressions with the capacity factor on a single nonpolar column (DB-5ms) yielded the best results for both CBzs and PCNs. Using the best regression equations, K-OA values for 6 CBzs and 27 PCNs were obtained for the temperature range from 10 degreesC to 50 degreesC. The internal energies of air-octanol phase transfer Delta(OA)U for these chemicals were calculated by correlating the interpolated log K-OA values with reciprocal absolute temperature.