【摘要】 用批处理的方法测定了泥沙碱性可提取腐殖质对双酚A(BPA)和两种典型类固醇(17β-雌二醇(E2)和17α-乙炔基雌二醇(EE2))的吸附规律,分析了泥沙碱性可提取腐殖质的荧光光谱特征;探讨了腐殖质荧光光谱特征与BPA、E2和EE2吸附的关系.结果表明,泥沙碱性可提取腐殖质占泥沙总有机碳含量的9.3%~27.1%,BPA、E2和EE2三种物质的标化分配系数logKoc(hs)值变化范围分别为:3.14~4.09、3.47~4.33和3.65~4.32,其平均值大小顺序为EE2>E2>BPA,与3种物质辛醇水分配系数大小顺序一致.不同泥沙碱性可提取腐殖质的荧光光谱都有2个特征峰,其位置分别在Ex/Em=(310~330nm)/(390~400nm)(α)和Ex/Em=(250~260nm)/(400~450nm)(α′);2个特征峰峰强度比值(Iα′/Iα)变化范围为0.46~1.64;而且,泥沙中富里酸的荧光光谱与碱性可提取腐殖质的类似.腐殖质荧光光谱特征峰α由相对稳定、高分子量的芳香性类富里酸物质产生,随着芳香性类富里酸物质含量的增加Iα′/Iα值减小,因此,BPA、E2和EE2三种物质的logKoc(hs)与Iα′/Iα值间存在线性关系.更多还原

【Abstract】 Humic substances (HS) have a critical influence on the sorption of organic contaminants by soils and sediments. In this research, the sorption behaviors of three representative endocrine disruptors, bisphenol A (BPA), 17β-estradiol (E2), and 17α-ethynylestradiol (EE2), onto sediments and HS extracted sediments were investigated using a batch technique. The organic carbon-normalized partition coefficients for humic substances (Koc(hs)) were calculated according to the difference of sorption coefficients between sediment and extracted sediments. The fluorescence spectra of different sediment HS were gained using excitation/emission matrix (EEM). The potential relations between the fluorescence of HS and the logKoc(hs) of selected endocrine disruptors were analyzed. The results show that the logKoc(hs) values range from 3.14 to 4.09 for BPA, from 3.47 to 4.33 for E2, and from 3.65 to 4.32 for EE2. The mean logKoc(hs) values for the three endocrine disruptors are ordered as follows: EE2> E2> BPA, which corresponds to the octanol-water partitioning coefficients (logKow). Two characteristic excitation-emission peaks were observed for HS samples extracted from sediments collected in different rivers of China. They are located at Ex/Em=(250~260 nm)/(400~450 nm) (peak α′) and Ex/Em=(310~330 nm)/(390~400 nm)(peak α) respectively. The similarity between FA Ex/Em pairs and those observed for HS indicates that FA is the predominant fraction of HS extracted from sediments. The α′ and α peak relative intensities (Iα′/Iα) vary from 0.46 to 1.64 for HS samples. Moreover, the logKoc(hs) values of BPA, E2, and EE2 have a negative linear correlation to Iα′/Iα values. Peak α is often attributed to ubiquitous, relatively stable and high molecular weight aromatic fulvic-like matter. Therefore, the result reveals that the abundance of aromatic rings in HS molecular structure plays a critical role in the sorption of selected endocrine disruptors.更多还原