Prediction of soil sorption coefficients using model molecular structures for organic matter and the quantum mechanical COSMO-SAC model.
Prediction of soil sorption coefficients using model molecular structures for organic matter and the quantum mechanical COSMO-SAC model.
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DOI：
10.1021/es102760x
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发表时间：
2011-02
影响因子：
11.4
通讯作者：
Kathy L. Phillips;Dominic M. Di Toro;S. Sandler
中科院分区：
文献类型：
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作者：
Kathy L. Phillips;Dominic M. Di Toro;S. Sandler
土壤吸附系数K(OC)是影响有机分子环境去向的重要参数。与测量K(OC)相关的困难导致了许多预测这一性质的尝试，但大多数依赖于根据与测量的K(OC)数据的相关性确定的土壤相的经验描述符，因此受到数据质量和多样性的限制。提出了一种预测只需分子结构的非离子有机化合物K(OC)的新方法。不执行校准。利用文献中的模型胡敏酸(HA)和富里酸(FA)分子结构，将土壤有机质模拟为由HA或FA分子组成的有机溶剂。K(OC)被用基于量子力学的COSMO-SAC模型预测为有机溶剂-水分配系数。一组440种不同的环境相关化学品的对数K(OC)值的预测均方根误差为0.84-1.08，这取决于使用的是HA模型还是FA模型。
The soil sorption coefficient, K(OC), is an important property affecting the environmental fate of organic molecules. Difficulties associated with measuring K(OC) have led to many attempts to predict this property, but most rely on empirical descriptors for the soil phase determined from correlations with measured K(OC) data, and are thereby limited by the data quality and diversity. A new method is presented to predict K(OC) for nonionic organic compounds that requires only molecular structures. No calibration is performed. Using model humic acid (HA) and fulvic acid (FA) molecular structures from the literature, the soil organic matter is modeled as an organic solvent composed of HA or FA molecules. K(OC) is predicted as an organic solvent-water partition coefficient using the quantum mechanics-based model COSMO-SAC. The log K(OC) values for a set of 440 diverse, environmentally relevant chemicals are predicted with a root-mean-square error of 0.84-1.08, depending on which model HA or FA is used.