Lazare Jovian, Tebes-Stevens Caroline, Weber Eric J, Shields Lindsay K
Oak Ridge Institute for Science and Education (ORISE), Hosted at U.S. Environmental Protection Agency, Athens, Georgia 30605, United States.
Center for Environmental Measurement and Modeling, United States Environmental Protection Agency, Athens, Georgia 30605, United State.
Environ Sci Technol. 2025 Jun 17;59(23):11745-11755. doi: 10.1021/acs.est.4c11596. Epub 2025 Jun 4.
Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are used in many applications due to their attractive nonstick and fire-fighting properties. When released into aquatic environments, commercial PFAS and associated byproducts may be transformed by hydrolysis to form more persistent products. For example, hydrolysis of perfluorinated carboxylic acid esters leads to perfluorinated carboxylic acids (PFCAs) and fluorotelomer alcohols (FTOHs). Quantitative structure activity relationships (QSARs) previously developed for predicting carboxylic acid ester hydrolysis rates are assessed for their predictive performance for perfluorinated molecules using compiled perfluorinated alkyl ester hydrolysis data. The assessment indicates that the model(s) are capable of estimating half-lives of various chain-lengths of perfluorinated alkyl esters; however, predictive performance could be improved through more accurate calculated chemical descriptor values for precursors of PFCAs. In particular, more accurate estimated p values are needed to improve hydrolysis rate predictions. The performance of several available cheminformatic applications (ChemAxon, SPARC, pkasolver, MolGpka and OPERA) is assessed for estimating p values for PFCAs and FTOHs, highlighting the need for improvements in predicting p values for longer-chain PFAS with perfluorinated α-carbons adjacent to the OC═O ester group.
全氟烷基和多氟烷基物质（PFAS）因其具有吸引人的不粘和灭火特性而被广泛应用于许多领域。当释放到水生环境中时，商业PFAS及其相关副产物可能会通过水解作用转化为更持久的产物。例如，全氟羧酸酯的水解会生成全氟羧酸（PFCA）和氟调聚物醇（FTOH）。利用汇编的全氟烷基酯水解数据，评估了先前开发的用于预测羧酸酯水解速率的定量构效关系（QSAR）对全氟分子的预测性能。评估表明，该模型能够估计各种链长的全氟烷基酯的半衰期；然而，通过为PFCA的前体提供更准确的计算化学描述符值，可以提高预测性能。特别是，需要更准确的估计p值来改进水解速率预测。评估了几种可用的化学信息学应用程序（ChemAxon、SPARC、pkasolver、MolGpka和OPERA）在估计PFCA和FTOH的p值方面的性能，强调了在预测与OC═O酯基相邻的具有全氟α-碳的长链PFAS的p值方面需要改进。
