【摘要】 通过多浓度盐溶液提取手段,三维荧光光谱技术与紫外吸收光谱技术,结合平行因子分析方法,对江汉平原沉积物溶解性有机质（DOM）的组成及结构特征进行分析,并探讨了沉积物DOM与NH₄-N及Fe²⁺的关系。结果表明,不同浓度盐溶液可提取出DOM中不同组分,其中,稀盐溶液提取组分（WEOM）主要为色氨酸类蛋白质荧光组分,具有分子量相对小、结构简单、稳定性差的特点;浓盐提取组分（SEOM）则以类腐殖质荧光组分为主具有稳定性高且分子量大的特点。随沉积深度,WEOM迁移能力呈现出先增加后降低的趋势。光谱参数对比结果揭示不同岩性、不同含水条件,影响着WEOM的物质组成及结构特征,在水流交替的开放环境下,WEOM多由低分子量、分子结构简单的组分组成,在相对封闭环境中,WEOM多由高分子量,分子结构复杂的组分组成。环境因子NH₄-N、Fe²⁺与WEOM的共变关系表明,WEOM贡献于水环境中N循环及物质组成。研究表明,沉积物有机质中含有结构、性质与来源截然不同的组分,不同岩性、不同含水条件同一组分的结构与性质也存在差异,研究成果为分析沉积物有机质的环境意义提供新思路。更多还原

【Abstract】 The components and structure characteristics of dissolved organic matter( DOM) in deep sediments of Jianghan plain were analyzed using multi-concentration salt solution extraction method,three-dimensional fluorescence spectrometry combined with parallel analysis( EEMs-PARAFAC) and ultraviolet absorption spectroscopy The correlation between DOM and NH4-N and Fe2 +were explored. The results showed that differentcomponents in DOM can extracted by different concentrations of salt solution. Among them,the water-extractable component( WEOM)is mainly the tryptophan protein-like. The fluorescent component has relatively small molecular weight,simple structure and poor stability. The concentrated salt extractable component( SEOM) is characterized by high stability and high molecular weight,mainly composed of humic-like fluorescent components. With the depth of deposition,the migration capacity of WEOM showed a trend of increasing first and then decreasing. Comparison results of spectrum parameter suggested that the component and structure of WEOM were affected by the lithologiesand saturated conditions. WEOM were made of low molecular weight and simple molecular structure in open system environment.While in relatively closed environment,WEOM were composed of high molecular weight and complex molecular structure. Covariant relationship between environmental factors include NH4-N,Fe2 +and dissolved organic matter shows that N circulation and material composition,in water environmental,were affected by WEOM. The result shows that the sediment organic matter were made of components which have different structures,properties and sources. The structure and properties of the same component with different lithology and different water conditions are also different. The research results provide new information for analyzing theenvironmental significance of sediment organic matter.更多还原