Liu Ben-ding, Li Xia, Dai Jing-yu
College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2007 Oct;27(10):2032-7.
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.
为了真正理解含有多种物质的黄腐酸的特性和结构，作者根据黄腐酸明确的性质及其结构相似的特点对其进行了详细分离。带有H⁺的黄腐酸可被用常规缓冲液（pH 2）平衡的XAD - 8柱吸附。利用不同pH值（4.8、7.0和11.0）的缓冲液可将黄腐酸中的亲水性部分分为三组，而疏水性部分则分别用蒸馏水和乙醇分为两组。为进行傅里叶变换红外光谱（FTIR）和核磁共振（NMR）光谱分析，使用了三种水稻土。可以得出结论，在低pH值下溶解的氧和羧基含量比在水和乙醇中溶解的更多，但脂肪族部分的含量较少且侧链较短。
