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应用紫外-可见光谱、傅里叶红外光谱与三维荧光光谱,对采自滇池外海及湖滨农田的2种典型陆生植物(玉米、紫茎泽兰)和5种水生植物(芦苇、水红花、水葫芦、眼子菜、茭草)所提取的DOM(溶解性有机质)组分进行了光谱分析.结果表明,陆生与水生植物DOM的紫外-可见光谱曲线基本类似,吸光度均随波长的增加而降低.陆生植物DOM的SUVA254(单位溶解性有机碳浓度下波长254 nm处吸收系数)值大于水生植物,表明滇池外源输入的DOM腐殖化程度大于内源.植物叶中DOM的A250/A365(A250、A365分别为波长250和365 nm处的紫外吸光度比值)小于茎,表明叶中DOM的芳香性和分子量都大于茎.陆生与水生植物DOM均有相似的红外特征峰带,其中—COO-、—CH2、—CO、—OH、—NH2的特征峰明显,表明它们是构成陆生和水生植物DOM的主要官能团.三维荧光光谱分析表明,陆生植物茎的DOM中含有类富里酸物质,而叶的DOM中含有类腐殖酸物质.水生植物除了水葫芦叶的DOM中含有类腐殖酸物质外,其他样品无论茎、叶都含有类富里酸物质.除水葫芦叶外,同种植物茎的DOM中存在类色氨酸物质,而叶中不存在.
Using two kinds of typical terrestrial plants (maize, Eupatorium adenophorum) and five kinds of aquatic plants (Phragmites australis, Safflower flower) collected from the outer sea and lakeside farmland in Dianchi Lake by UV-Vis, FTIR and three- , Water hyacinth, Zizyphus jujubae), and DOM (dissolved organic matter) extracted from the soil were analyzed spectrophotometrically.The results showed that the UV-Vis spectra of terrestrial and aquatic plants were basically similar, and the absorbance was in accordance with the wavelength Increased (P <0.05), and SUVA254 (absorption coefficient at 254 nm) of terrestrial plant DOM was greater than that of aquatic plants, indicating that the degree of DOM humification in Dianchi Lake was higher than that in endogenous DOM A250 / A365 (A250, A365, UV absorbance ratio at wavelengths of 250 and 365 nm, respectively) was smaller than that of stems, indicating that the aromaticity and molecular weight of DOM in leaves were greater than those in stems. Both terrestrial and aquatic DOM had similar infrared peak bands , In which the characteristic peaks of -COO -, --CH2, -CO, -OH, -NH2 are obvious, indicating that they are the main functional groups that make up the DOM of terrestrial and aquatic plants.Three-dimensional fluorescence spectroscopy analysis showed that the terrestrial DOM Contains class fulvic acid , While the leaf DOM contains humic acid species in the aquatic plants in addition to water hyacinth leaf DOM containing humus species, the other samples regardless of stems and leaves contain the type of fulvic acid substances in addition to water hyacinth leaves, the same The tryptophan-like substance is present in the DOM of the plant stem, but not in the leaves.