College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, Jinhua 321004, China.
Molecules. 2022 Nov 6;27(21):7608. doi: 10.3390/molecules27217608.
Polycyclic aromatic hydrocarbons (PAHs) and their oxygen/nitrogen derivatives released into the atmosphere can alternate between a gas phase and a particulate phase, further affecting their environmental behavior and fate. The gas/particulate partition coefficient (KP) is generally used to characterize such partitioning equilibrium. In this study, the correlation between log KP of fifty PAH derivatives and their n-octanol/air partition coefficient (log KOA) was first analyzed, yielding a strong linear correlation (R2 = 0.801). Then, Gaussian 09 software was used to calculate quantum chemical descriptors of all chemicals at M062X/6-311+G (d,p) level. Both stepwise multiple linear regression (MLR) and support vector machine (SVM) methods were used to develop the quantitative structure-property relationship (QSPR) prediction models of log KP. They yield better statistical performance (R2 > 0.847, RMSE < 0.584) than the log KOA model. Simulation external validation and cross validation were further used to characterize the fitting performance, predictive ability, and robustness of the models. The mechanism analysis shows intermolecular dispersion interaction and hydrogen bonding as the main factors to dominate the distribution of PAH derivatives between the gas phase and particulate phase. The developed models can be used to predict log KP values of other PAH derivatives in the application domain, providing basic data for their ecological risk assessment.
多环芳烃（PAHs）及其含氧/含氮衍生物释放到大气中后，可在气相和颗粒相之间相互转化，从而进一步影响它们的环境行为和归宿。通常使用气/粒分配系数（KP）来描述这种分配平衡。本研究首先分析了 50 种 PAH 衍生物的 log KP 与正辛醇/空气分配系数（log KOA）之间的相关性，发现两者之间存在很强的线性相关性（R2 = 0.801）。然后，使用 Gaussian 09 软件在 M062X/6-311+G（d，p）水平上计算了所有化合物的量子化学描述符。采用逐步多元线性回归（MLR）和支持向量机（SVM）方法分别建立了 log KP 的定量构效关系（QSPR）预测模型。这些模型的统计性能（R2 > 0.847，RMSE < 0.584）优于 log KOA 模型。进一步采用模拟外部验证和交叉验证来评价模型的拟合性能、预测能力和稳健性。机制分析表明，分子间色散相互作用和氢键是控制 PAH 衍生物在气相和颗粒相之间分配的主要因素。所开发的模型可用于预测应用域中其他 PAH 衍生物的 log KP 值，为其生态风险评估提供基础数据。
