| Fulvic acid (FA) is one of the most important components of natural organic matter. FAs has been shown to strongly influence a wide range of environmentally important process. FAs has postulated to be one of the most important factors controlling the rates of mineral dissolution in soils and sediments. Sorbed FA may also strongly influence the physical and chemical properties of the colloidal particles in natural waters, and as a consequence help to control the transport of organic and inorganic pollutants. Therefore, the research to the chemical properties and topography of different FA components in soil is very important for us to learn much better about FAs.In this work, the soil samples were taken from TieLi Forestry Bureau of Xiaoxinganling.,then a much more comprehensive wet chemical procedure was used for fractionation and quantitative isolation sediment organic matter (SOM) into four fractions:fulvic acid FA-1,FA-2,FA-3 and FA-4, and the physical and chemical properties were analysed in this research. Meanwhile, the AFM and Py-Gc-MS were utilized to research the origin, character and topography of different FAs components. The result of AFM showed us that the size of molecular particle of each FA component distributed in a near range, and the topography of FAs were almost spherical which meant the FAs of soil had a homogeneous topography. The products of Py-Gc-MS mainly included soil lipid, aromatic compounds, polysaccharide, polyaromatic compounds, phenol and formic ester. All these products indicated that the sources of FA were multiple, not only including some parts of plant itself, epidermis and corneums of plants, soft lignin of the roots, but the temnants of microorganism activities. Owning these information was very helpful for us to better understand the importance of FA in the process of soil and environment. |
