Experimental and QSPR study of sorption properties of polychlorinated diphenyl sulfides (PCDPSs) in Yangtze River plain soil

This work investigates the soil sorption activity of polychlorinated diphenyl sulfides (PCDPSs) assessed by both batch equilibration and quantitative structure property relationship (QSPR) methodologies. Sorption isotherms of diphenyl sulfide (DPS) and 2,4′-dichloro diphenyl sulfide (2,4′-di-CDPS) were obtained for different ionic strengths and the soil partition coefficients (logKoc) of 20 PCDPSs were determined. Compared to Langmuir and Freundlich isotherms, the linear isotherm fits are better for the low concentration sorption of DPS and 2,4′-di-CDPS. The results indicate that logKoc of the 20 PCDPSs increase along with logKow. For predicting the logKoc of 194 PCDPSs, the partial least square (PLS) method was used to generate a QSPR model with 18 descriptors. By cross validation, the model shows good verifying precision and excellent predictive ability.

► Soil partition coefficients (logKoc) were measured for 20 PCDPSs.
► Sorption capacities of the PCDPSs increased with the increasing of ionic strength.
► How substituted chlorine atom number and logKow affect sorption is revealed.
► Satisfactory PLS models were established to predict logKoc of 194 PCDPS congeners.