Faculty of Chemistry, Laboratory of Environmental Chemometrics, University of Gdańsk, ul. Sobieskiego 18, 80-952, Gdańsk, Poland.
Mol Divers. 2011 Feb;15(1):173-88. doi: 10.1007/s11030-010-9250-9. Epub 2010 Apr 13.
We have estimated degradation half-lives of both brominated and chlorinated dibenzo-p-dioxins (PBDDs and PCDDs), furans (PBDFs and PCDFs), biphenyls (PBBs and PCBs), naphthalenes (PBNs and PCNs), diphenyl ethers (PBDEs and PCDEs) as well as selected unsubstituted polycyclic aromatic hydrocarbons (PAHs) in air, surface water, surface soil, and sediments (in total of 1,431 compounds in four compartments). Next, we compared the persistence between chloro- (relatively well-studied) and bromo- (less studied) analogs. The predictions have been performed based on the quantitative structure-property relationship (QSPR) scheme with use of k-nearest neighbors (kNN) classifier and the semi-quantitative system of persistence classes. The classification models utilized principal components derived from the principal component analysis of a set of 24 constitutional and quantum mechanical descriptors as input variables. Accuracies of classification (based on an external validation) were 86, 85, 87, and 75% for air, surface water, surface soil, and sediments, respectively. The persistence of all chlorinated species increased with increasing halogenation degree. In the case of brominated organic pollutants (Br-OPs), the trend was the same for air and sediments. However, we noticed that the opposite trend for persistence in surface water and soil. The results suggest that, due to high photoreactivity of C-Br chemical bonds, photolytic processes occurring in surface water and soil are able to play significant role in transforming and removing Br-OPs from these compartments. This contribution is the first attempt of classifying together Br-OPs and Cl-OPs according to their persistence, in particular, environmental compartments.
我们已经估算了空气、地表水、表层土壤和沉积物（共计四个部分中的 1431 种化合物）中溴代和氯代二苯并对二恶英（PBDD 和 PCDD）、呋喃（PBDF 和 PCDF）、联苯（PBB 和 PCB）、萘（PBN 和 PCN）、二苯醚（PBDE 和 PCDE）以及部分未取代的多环芳烃（PAH）的降解半衰期。接下来，我们比较了氯代（研究较多）和溴代（研究较少）类似物之间的持久性。预测是基于定量构效关系（QSPR）方案，使用 K 最近邻（kNN）分类器和半定量持久性分类系统进行的。分类模型利用主成分分析（Principal Component Analysis，PCA）从一组 24 个结构和量子力学描述符中得出的主成分作为输入变量。基于外部验证的分类准确性分别为空气、地表水、表层土壤和沉积物的 86%、85%、87%和 75%。所有氯化物种的持久性都随卤化程度的增加而增加。对于溴代有机污染物（Br-OPs），在空气和沉积物中也是如此。然而，我们注意到在地表水和土壤中，持久性的趋势相反。结果表明，由于 C-Br 化学键的高光反应性，发生在地表水和土壤中的光解过程能够在这些部分中发挥重要作用，转化和去除 Br-OPs。这是首次根据持久性（特别是环境部分）对 Br-OPs 和 Cl-OPs 进行分类的尝试。
