Identifying structural characteristics of humic acid to static and dynamic fluorescence quenching of phenanthrene, 9-phenanthrol, and naphthalene
Identifying structural characteristics of humic acid to static and dynamic fluorescence quenching of phenanthrene, 9-phenanthrol, and naphthalene
复制标题
鉴定腐植酸对菲、9-菲酚和萘的静态和动态荧光猝灭的结构特征
DOI：
10.1016/j.watres.2017.06.010
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发表时间：
2017
期刊：
影响因子：
12.8
通讯作者：
Xing Baoshan
中科院分区：
文献类型：
--
作者：
Wang Lin;Li Hao;Yang Yu;Zhang Di;Wu Min;Pan Bo;Xing Baoshan
荧光猝灭是一种灵敏、快速的方法，可以定量荧光有机污染物与猝灭剂（如溶解有机物（DOM））之间的相互作用。动态荧光猝灭是由于分子碰撞而不是真实的结合，因此它使结合数据解释复杂化。另一方面，基态的荧光污染物发生静态荧光猝灭，这降低了自由溶解的污染物的浓度。然而，DOM中的特定结构对荧光污染物的静态和动态荧光猝灭的影响尚不清楚，这极大地阻碍了荧光猝灭技术的应用。对从沉积物中提取的腐殖酸（HA）进行化学改性，漂白、酸水解和脱羧。在这些修饰之前和之后的HA用于菲（PHE）、9-菲咯（PTR）和萘（NAP）的荧光猝灭实验。不同的淬灭机制，观察到这些化学品取决于HA性能。对于PHE和NAP，芳香族组分表现为静态猝灭，而羧基主要表现为动态猝灭。芳香族化合物和碳水化合物在HA主要绑定（静态淬灭），而不是碰撞（动态淬灭）与PTR。只有当羧基在苯环上时，羧基才能通过动态猝灭与PTR相互作用。基于这些结果，我们强调在荧光猝灭研究中应小心地排除动态猝灭。这条线的研究是很重要的DOM属性和静态/动态淬火贡献之间建立一个一般的关系。
Fluorescence quenching is a sensitive and fast method to quantify the interactions between a fluorescent organic contaminant and a quencher, such as dissolved organic matter (DOM). Dynamic fluorescence quenching is resulted from molecular collision, not the real binding, and thus it complicates the binding data interpretation. On the other hand, static fluorescence quenching occurs for fluorescent contaminants of ground states, which decreases the concentration of freely dissolved contaminants. However, how a particular structure in DOM contributes to the static and dynamic fluorescence quenching of a fluorescent contaminant is still unclear, which has greatly hindered the application of fluorescence quenching technique. A humic acid (HA) extracted from sediment was chemically modified, i.e., bleaching, acid hydrolysis, and decarboxylation. HAs before and after these modifications were used in fluorescence quenching experiments for phenanthrene (PHE), 9-phenanthrol (PTR) and naphthalene (NAP). Different quenching mechanisms were observed for these chemicals depending on HA properties. For PHE and NAP, aromatic components showed static quenching, while carboxyl groups primarily showed dynamic quenching. Aromatic components and carbohydrates in HAs primarily bound (static quenching) rather than collided (dynamic quenching) with PTR. Carboxyl groups showed interactions with PTR through dynamic quenching only when carboxyl groups were on the benzene ring. Based on the results, we emphasized that dynamic quenching should be carefully excluded in fluorescence quenching studies. This line of study is important to establish a general relationship between DOM properties and static/dynamic quenching contributions.