XAD树脂分组水稻土富里酸组分的脂肪族特性

为准确把握由多种物质组成的富里酸的化学性质及结构，将富里酸按一定的性质及构造相似的特征进行细划分，从而减小富里酸的复杂性。该研究以通用缓冲液(pH 2)平衡后的XAD-8树脂能吸附H+型富里酸，利用pH 4.8，pH 7.0，pH 11.0的该通用缓冲液，可将富里酸中亲水性物质按解离程度分离为三种组分，再用水、乙醇将富里酸中的疏水性物质划分为的强、弱两部分。分析各组分的元素组成，红外光谱和核磁共振(1HNMR)的特征，认为在低pH缓冲液溶出的组分中含氧量、羧基含量高于水和乙醇溶出的组分，而脂肪性成分含量则低于水和乙醇溶出的组分，并且脂肪族侧链较短。

Aliphatic Characteristics of the Fractions Isolated from the Soil Fulvic Acid Using XAD-8 Column

In order to truly understand the character and structure of fulvic acid,which contains many substances,the authors isolated fulvic acid detailedly according to its definite character and its characteristic of similar structure.Fulvic acid with H can be adsorbed by the XAD-8 column balanced by the usual buffer(pH 2).The hydrophilic fraction in fulvic acid can be divided into three groups using the buffer with various pH(4.8,7.0 and 11.0),while the hydrophobic fraction can be classified into two groups by the distilled water and alcohol separately.For FTIR(Fourier transform infrared)and NMR(nuclear magnetic resonance)spectroscopy analysis,three paddy soils were used.It may be concluded that the content of oxygen and carboxyl group dissolved at low pH is more than that dissolved in the water and alcohol,but the content of aliphatic fraction is less and has short side chain.