基于TLSER和QSPR关系预测PAHs和PCBs的LDPE膜-空气分配系数

有机污染物在被动采样材料与环境介质之间的平衡分配系数(K_P),是测定环境中有机污染物浓度的重要参数,但K_P值大部分都需要经过繁琐的实验测定获取,无法逐个测定数量繁多的污染物,因此需开发一种预测K_P值的方法。为此,搜集整理了一些多环芳香烃(PAHs)和多氯联苯(PCBs)的低密度聚乙烯(LDPE)-空气分配系数(K_PA)的实测值,基于理论线性溶解能(TLSER)和定量结构性质关系(QSPR),利用逐步多元线性回归(MLR)分别构建了预测K_PA值的模型。模型的决定系数R2adj分别为0.927和0.956,交叉验证系数Q2LOO分别为0.915和0.946,外部系数Q2ext分别为0.913和0.960。结果表明,2种模型具有良好的拟合优度、稳健性和预测能力,并解释了模型的机理。所构建的2种模型均可用来预测应用域内有机污染物的LDPE膜-空气分配系数。

Development of TLSER and QSPR Models for Predicting LDPE-air Partition Coefficients of PAHs and PCBs

The partition coefficients of organic contaminants between polymer and air (K_P) are significant for designing passive sampler devices. Most of the K_P values are usually obtained from experimental measurements, which are not readily available for most of the polar and non-polar neutral organic chemicals. Therefore, current work aimed to establish mathematical models for predicting K_P values with the physicochemical properties of chemicals of interest. To make further improvements in measuring K_PA values, current study focused to develop theoretical linear solvation energy relationship (TLSER) and the quantitative structure-property relationship (QSPR) models for predicting polymer-water partition coefficients. The results of stepwise multiple regression indicated that both models fits well with objectives, and had robustness and predictive capacity. These two models had similar statistical results of adjusted determination coefficients (R²_adj) of 0.927 and 0.956, cross-validation coefficients (Q²_LOO) of 0.915 and 0.946, and external validation coefficients (Q²_ext ) of 0.913 and 0.960, respectively. Mechanism interpretation suggested that the main factors governing the partition process between LDPE and air were the molecular polarizability and hydrophobicity. Current findings provide an excellent tool for predicting acute K_PA values for most of the common hydrophobic organic compounds within the applicability domains.