Cuypers Chiel, Grotenhuis Tim, Nierop Klaas G J, Franco Elena Maneiro, de Jager Adrie, Rulkens Wim
Environmental Technology Department, Wageningen University, The Netherlands.
Chemosphere. 2002 Sep;48(9):919-31. doi: 10.1016/s0045-6535(02)00123-6.
The composition of amorphous and condensed soil/sediment organic matter (SOM) domains was investigated for one soil sample and four sediment samples. These samples were oxidized with persulfate to remove amorphous SOM, before and after which the composition of SOM was studied by thermogravimetric analysis, pyrolysis-GC/MS, and cross polarization magic angle spinning 13C-NMR. Comparison of the SOM composition before and after oxidation showed that condensed SOM was more thermostable and less polar than amorphous SOM. Condensed SOM was relatively low in O-alkyl C and carboxyl C and it was likely to contain only small amounts of labile organic components (carbohydrates, peptides, fatty acids). Apart from these general characteristics, the composition of the condensed and amorphous domains appeared to be highly dependent on the origin and nature of the SOM investigated. Condensed domains in relatively undecomposed SOM were enriched in aliphatic C, whereas condensed domains in relatively weathered SOM were enriched in aromatic C. Altogether, the compositional changes upon persulfate oxidation were similar to the compositional changes upon humification, which supports the idea that weathered SOM is more condensed than the original material.
对一个土壤样品和四个沉积物样品的无定形和凝聚态土壤/沉积物有机质（SOM）域的组成进行了研究。这些样品先用过硫酸盐氧化以去除无定形SOM，然后在氧化前后通过热重分析、热解-气相色谱/质谱联用和交叉极化魔角旋转13C-核磁共振研究SOM的组成。氧化前后SOM组成的比较表明，凝聚态SOM比无定形SOM更具热稳定性且极性更低。凝聚态SOM中O-烷基碳和羧基碳含量相对较低，可能仅含有少量不稳定有机成分（碳水化合物、肽、脂肪酸）。除了这些一般特征外，凝聚态和无定形域的组成似乎高度依赖于所研究SOM的来源和性质。相对未分解的SOM中的凝聚态域富含脂肪族碳，而相对风化的SOM中的凝聚态域富含芳香族碳。总之，过硫酸盐氧化后的组成变化与腐殖化后的组成变化相似，这支持了风化SOM比原始物质更凝聚的观点。
