Abstract：
Copper-based algicides have been widely used to suppress algae blooms; however, the release of algal organic matter (AOM) on account of cell lysis may cause significant changes in the mitigation, transformation, and bioavailability of Cu(II). In the present work, the binding characteristics of Cu(II) with AOM were explored via combinative characterization methods, such as high-performance size exclusion chromatography, differential absorption spectra analysis, and joint applications of two-dimensional correlation spectroscopy (2D-COS), as well as heterospectral 2D-COS and moving window 2D-COS analyses of UV, synchronous fluorescence, and FTIR spectra. Carboxyl groups displayed a preferential interaction to Cu(II) binding, followed by polysaccharides. The spectral changes of C]O stretching occur after the change of chromophores in complexation with Cu(II). The AOM chromophores exhibit obvious conformations at Cu(II) concentrations higher than 120 μM, while AOM fluorophores and functional groups exhibit the greatest changes at Cu(II) concentrations lower than 20 μM. All these observations have verified the presence of binding heterogeneity and indicate that AOM could interact with Cu(II) through diverse functional moieties. Therefore, our study contributes to the better understanding of the fate of Cu(II)-AOM complexes in aquatic systems.
摘要：
铜基灭藻剂已被广泛用于抑制藻类繁殖；然而，由于细胞裂解而释放的藻类有机物（AOM）可能会导致缓解的显着变化，改造,和Cu(II)的生物有效性。在目前的工作中,通过组合表征方法探索了Cu(II)与AOM的结合特性，如高效尺寸排阻色谱法，差分吸收光谱分析，以及二维相关光谱(2D-COS)的联合应用，以及紫外的异光谱2D-COS和移动窗口2D-COS分析，同步荧光,和FTIR光谱。羧基对Cu（II）结合表现出优先的相互作用，其次是多糖。C]O拉伸的光谱变化发生在与Cu（II）络合的发色团变化之后。AOM发色团在Cu（II）浓度高于120μM时表现出明显的构象，而AOM荧光团和官能团在Cu（II）浓度低于20μM时表现出最大的变化。所有这些观察都证实了结合异质性的存在，并表明AOM可以通过不同的功能部分与Cu（II）相互作用。因此,我们的研究有助于更好地了解水生系统中Cu（II）-AOM复合物的命运。
