Size distribution of condensed aromatic rings in various soil humic acids
Size distribution of condensed aromatic rings in various soil humic acids
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DOI：
10.1016/j.orggeochem.2010.10.006
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发表时间：
2011-01-01
影响因子：
3
通讯作者：
Watanabe, Akira
中科院分区：
文献类型：
--
作者：
Ikeya, Kosuke;Hikage, Tatsuo;Watanabe, Akira
稠环结构是腐植酸在环境中的重要骨架成分，具有很强的抗腐性。然而，它们没有得到广泛的研究。通过透射电子显微镜（TEM）和X射线衍射（XRD）分析，获得了不同土壤中HAs稠环的相对含量和组成（粒径分布）。在所有HA的XRD曲线中，清楚地观察到源自碳层平面的11带。11带的分析表明，在HA中的碳层平面的大小范围为0.48-1.68 nm，对应于4- 37-环稠合芳族结构。颜色越深、芳香碳含量越高的羟基磷灰石，其总碳层平面和大碳层平面的含量越高。同时，HA中的碳层平面小于炭黑参照物中的碳层平面（从0.24至>3.66 nm）。在TEM分析中，在HA中观察到的条纹比在炭黑中观察到的条纹更不清晰和更不有序，这与XRD结果一致。(C)2010爱思唯尔有限公司版权所有。
Condensed aromatic rings are important skeletal components with regard to the recalcitrant nature of humic acids (HAs) in the environment. However, they have not been extensively studied. The relative content and composition (size distribution) of condensed aromatic rings in HAs were obtained from various soils subjected to transmission electron microscopy (TEM) and X-ray diffraction (XRD) profile analysis. In the XRD profiles of all the HAs, the 11 band that was derived from the carbon layer planes was clearly observed. Analysis of the 11 band indicated that the size of the carbon layer planes in HAs ranged from 0.48-1.68 nm, corresponding to 4- to 37-ring condensed aromatic structures. The contents of the total and larger carbon layer planes were larger in HAs with darker color and larger aromatic carbon content. At the same time, the carbon layer planes in HAs were smaller than those in a carbon black reference (from 0.24 to >3.66 nm). In the TEM analysis, fringes observed in HAs were less distinct and less ordered than those in carbon black, which was in agreement with the XRD result. (C) 2010 Elsevier Ltd. All rights reserved.