巴松措表层沉积物中腐殖酸与富里酸的特性

采用紫外吸收光谱和GC-MS扫描解析，对西藏东南部湖泊巴松措表层沉积物中的腐殖酸和富里酸特性进行研究.结果表明，巴松措表层沉积物中腐殖酸和富里酸的紫外吸光度在200~400nm间较400~800nm间明显增加，富里酸在270nm附近出现弱而钝的双肩吸收，表明其中存在芳香环结构.腐殖酸和富里酸在254nm处的吸光度普遍偏低，表明其中难降解有机物的含量较低.通过紫外吸收特征值（A₄₆₅/A₆₆₅）分析得出，巴松措表层沉积物腐殖酸和富里酸的腐殖化程度较低.在人类活动频繁的区域，腐殖酸和富里酸的腐殖化程度相对于其他区域较高.根据GC-MS扫描解析，匹配度较高物质的分子式为C₁₅H₂₄，分子量为204，其结构中都含有芳香环，且含有脂肪链、不饱和烃、甲基、亚甲基、异丙基、环丙烷、己烷和萘等结构，均属于芳香族化合物，与紫外吸收光谱的分析结果一致.匹配度较高的物质推断属于类色氨酸.

Characterization of humic and fulvic acid in the surface sediments from Basong Lake in Tibet

Surface sediment samples from Basong Lake located in the south-eastern Tibet were collected and characterized by UV spectroscopy and GC-MS. The results showed that the UV absorbance of humic and fulvic acid in the lake surface sediments increased significantly from the 200~400nm range to the 400~800nm range. A weak and broad twin absorption peaks near 270nm in fulvic acid samples indicated the presence of aromatic ring structure. A generally low absorption of humic and fulvic acid at 254nm suggested a low content of non-degradable organic matter in the samples. The analysis of the characteristic values of UV absorption (A₄₆₅/A₆₆₅) showed that the humification degree in the surface sediments of Basong Lake was generally low. However, the degree of humification was relatively higher at the sampling sites with human disturbances. In accordance with the UV results, GC-MS analysis revealed that the humic and fulvic acid in the surface sediments from the lake consisted mainly of aromatic compounds, which were associated with aromatic ring and fatty chain, unsaturated hydrocarbons, methyl, methylene, isopropyl, cyclopropane, hexane and naphthalene groups. The molecular formula of highly matched structure was C₁₅H₂₄ with a molecular weight of 204, which were inferred to be tryptophan like.