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河流是有机物从陆地向海输送的重要纽带。研究河流沉积环境中有机物的来源、贡献和分布情况,对于评估陆源有机物的碳循环以及反演环境演变具有重要意义。本文以黄河济南段的柱状沉积物为例,利用碱性CuO把木质素氧化分解为不同的单体并通过GC-FID测定,初步探讨了木质素的垂直分布特征和有机物来源。研究结果表明:木质素的含量Σ8(mg/10gds)的变化范围0.0029~0.60mg/10gds,其Σ8的值整体较低,少数值几乎接近检出限,可能与黄河含沙量大,砂质颗粒物的有机质本身含量较低有关,同时低Σ8很好地揭示了沉积物样品的贫有机质特征;木质素的植被参数S/V和C/V表明其母源植被多以被子植物的叶或草为主,部分区段掺杂着裸子植物草本组织。其降解参数(Ad/Al和P/(V+S))则揭示了木质素经历了中高程度的氧化降解和较强的去甲基/去甲氧基降解。此外,C/V和3,5-Bd/V(3,5-双羟基苯甲酸/V)的关系说明该研究区域有机物主要来自土壤的贡献。
The river is an important link of organic matter from land to sea. Studying the origin, contribution and distribution of organic matter in river sedimentary environment is of great significance to evaluate the carbon cycle of terrestrial organic matter and to retrieve the evolution of the environment. Taking the columnar sediments in Jinan section of the Yellow River as an example, the lignin was oxidized and decomposed into different monomers by alkaline CuO. The vertical distribution characteristics of lignin and the origin of organic matter were discussed through GC-FID. The results showed that the content of Σ8 (mg / 10gds) ranged from 0.0029 to 0.60mg / 10gds, the value of Σ8 was low and the value of the Σ8 was almost close to the detection limit, which may be related to the sediment concentration of the Yellow River, The lower organic content of the particulate matter is related to the lower Σ8, which reveals the poor organic characteristics of the sediment samples. The vegetation parameters S / V and C / V of the lignin indicate that the maternal vegetation mostly contains leaves or grass of the angiosperm Mainly part of the section is doped with gymnosperm tissue of gymnosperms. The degradation parameters (Ad / Al and P / (V + S)) revealed that lignin underwent moderate and high levels of oxidative degradation and strong demethylation / demethoxy degradation. In addition, the relationship between C / V and 3,5-Bd / V (3,5-bishydroxybenzoic acid / V) indicates that the organic matter in the study area mainly comes from the soil.