| Abstract
| - In this study, general and class-specific QSPR models for soil sorption, logKOC, of 344 organic pollutants(0 < logKOC< 4.94) were developed using a large variety of theoretical molecular descriptors based onlyon molecular structure. Two general models were obtained. The first model was derived for a structurallyrepresentative set of 68 chemicals (R2=0.76, s=0.44), whereas the second involved a total of 344 compounds(R2=0.76, s=0.41). The first was validated using the data for the remaining 276 pollutants (R2=0.70, s=0.45).An additional validation of both models was performed using an independent set of 48 pollutants. Bothmodels predict the logKOC at the level of experimental precision, while the theoretical molecular descriptorsappearing in the QSPR models give further insight into the mechanisms of soil sorption. The analysis of thedistribution of the residuals of the logKOC values calculated by both general models indicated the need andpossible advantages of modeling soil sorption for smaller data sets related to individual classes of chemicals.Accordingly, QSPR models were also developed for 14 chemical classes. The descriptors appearing in thesemodels were discussed as related to the possible interaction mechanisms in soil sorption.
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