摘要
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.
By using UV-vis, Fourier transform infrared （FT-IR） and the three-dimensional excitation emission matrix fluorescence （3D- EEM） spectroscopies, chemical structures of water dissolved organic matters （DOM） were extracted from typical terrestrial and aquatic plants in or around the Dianchi Lake were investigated. The results showed that characters of UV-visible spectra were similar between the DOMs derived from the terrestrial and the aquatic plants. The ultraviolet absorbance of DOM samples decreased monotonically with increases of the wavelength. The SUVA2s4values of DOM derived from terrestrial plants were greater than those from aquatic plants, which indicated the higher humifieation degree of the DOM from the terrestrial. Ratios of A250 and A3650f the leaf DOMs were less than those of the stems, which illustrated that both aromaticity and molecular weight of leaf DOMs were higher than those of stem DOMs. The characteristic peaks of-CO0 - , -CH2 , -C =O, -OH and --NHzwere clearly shown in DOMs for both terrestrial and aquatic plants,and suggested that they would be the main function groups in DOMs of these species. The 3D-EEM spectrum showed that the DOMs from stems of the terrestrial plants contained fulvic acid and those from leaves have humic acid for these species. DOMs of stems and leaves of aquatic plants mainly contained fulvic acid, except the water hyacinth which had humic acid in its DOM. Except for the water hyacinth, DOMs from stems of all plants contained the tryptophan-like organic matters, but there were nosimilar fluorophore showed in their leaf DOMs.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2013年第1期72-79,共8页
Research of Environmental Sciences
基金
国家重点基础研究发展计划(973)项目(2008CB418200)
中央级公益性科研院所基本科研业务专项(2010KYYW04)
国家自然科学基金项目(41173094)
关键词
溶解性有机质
紫外-可见光谱
傅里叶红外光谱
三维荧光光谱
滇池
dissolved organic matters （DOM）
UV-vis spectroscopy
Fourier transform infrared （FT-IR） spectroscopy
three-dimensional excitation emission matrix fluorescence （3D-EEM） spectroscopy
Lake Dianchi
