ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
3 files

Predicting Partition Coefficients of Short-Chain Chlorinated Paraffin Congeners by COSMO-RS-Trained Fragment Contribution Models

preprint
revised on 27.09.2020 and posted on 28.09.2020 by Satoshi Endo, Jort Hammer
Chlorinated paraffins (CPs) are highly complex mixtures of polychlorinated n-alkanes with differing chain lengths and chlorination patterns. Knowledge on physicochemical properties of individual congeners is limited but needed to understand their environmental fate and potential risks. This work uses a sophisticated but time-demanding quantum chemically based method COSMO-RS and a fast-running fragment contribution approach to enable prediction of partition coefficients for a large number of short-chain chlorinated paraffin (SCCP) congeners. Fragment contribution models (FCMs) were developed using molecular fragments with a length of up to C4 in CP molecules as explanatory variables and COSMO-RS-calculated partition coefficients as training data. The resulting FCMs can quickly provide COSMO-RS predictions for octanol–water (Kow), air–water (Kaw), and octanol–air (Koa) partition coefficients of SCCP congeners with an accuracy of 0.1–0.3 log units root mean squared errors. The FCM predictions for Kow agree with experimental values for individual constitutional isomers within 1 log unit. The distribution of partition coefficients for each SCCP congener group was computed, which successfully reproduced experimental log Kow ranges of industrial CP mixtures. As an application of the developed FCMs, the predicted Kaw and Koa were plotted to evaluate the bioaccumulation potential of each SCCP congener group.

Funding

Environmental Restoration and Conservation Agency, Japan (JPMEERF18S20300)

History

Email Address of Submitting Author

endo.satoshi@nies.go.jp

Institution

National Institute for Environmental Studies (NIES)

Country

Japan

ORCID For Submitting Author

0000-0001-8702-1602

Declaration of Conflict of Interest

No conflict of interest

Version Notes

Version 1.0 (June 22, 2020) Version 2.0 (September 27 2020), with major revisions

Exports