论文部分内容阅读
腐植物质在自然环境中是重要的,在农业和工业中也是重要的。对来自煤、土壤和水体的腐植物质方面的工作得益于学科际合作和采用标准样品。可供选择的分离和分级腐植物质的方法被作了讨论。这些高度非均质的物质很不容易被分级成均匀级分。滴定方法证明腐植酸和黄腐酸是既含强酸又含弱酸基团的聚电解质。已经用超离心的方法分级到分子量范围跨越10~3到10~6的大小级分。它们的分子通常假设具有无规线团的构象,虽则也看到过更紧密的形状。红外和碳13核磁谱提供了功能基团存在的详细信息。顺磁共振谱表明有机质中存在不成对的电子,可能是醌氢醌络合物。通过酸、碱水解侦查到蛋白质、碳水化合物和酯的特征,并从氧化和钠还原降解产物阐明有芳香结构。裂解数据指出腐植酸和腐黑物彼此是紧密相关的,但黄腐酸则不然,它似乎大部分从碳水化合物演化而来。小心控制反应条件是进一步用降解技术阐明腐植物质结构的基本要求。
Humus is important in the natural environment and is also important in agriculture and industry. Work on humic substances from coal, soil and water benefits from inter-disciplinary cooperation and the use of standard samples. Alternative methods of separating and grading humic substances are discussed. These highly heterogeneous materials are not easily classified as uniform fractions. Titration shows that humic acid and fulvic acid are polyelectrolytes containing both strong and weak acid groups. Has been fractionated by ultracentrifugation to size fractions spanning 10-3 to 10-6 in the molecular weight range. Their molecules are usually assumed to have a random coil of conformation, though a tighter shape has also been seen. Infrared and carbon 13 nuclear magnetic spectra provide detailed information on the presence of functional groups. The paramagnetic resonance spectrum indicates the presence of unpaired electrons in the organic matter, possibly a quinone hydroquinone complex. Detection of protein, carbohydrate and ester characterization by acid and base hydrolysis and elucidation of aromatic structures from oxidation and sodium reduction degradation products. Cleavage data indicate that humic acid and humic substances are closely related to each other, but fulvic acid is not the case, it seems that most of them evolved from carbohydrates. Careful control of the reaction conditions is a further demonstration of the basic requirements for humic substance structure using degradation techniques.