黄芪中微量元素铜形态分析——与黄芪多糖作用机理研究

Speciation Analysis of Copper in Radix Astragali——Interactive Mechanism with Total Polysaccharide

采用水煎醇沉法从黄芪中提取黄芪多糖(TPA),用火焰原子吸收法测定了其中元素铜的含量;通过吸附平衡试验,研究了黄芪多糖对铜离子的吸附过程;结合光谱分析,探讨了黄芪中微量元素铜与活性成分多糖的作用机理。结果显示,黄芪多糖对铜离子的吸附过程符合Langmuir和Freundlich等温式,相关系数r分别大于0.99和0.9。黄芪多糖对水溶液中铜离子的吸附为非线性优惠吸附,主要吸附机理为表面络合,光谱分析显示主要吸附官能团为羟基和氨基。

Total polysaccharide of Astragalus （TPA） was obtained by aqueous extraction of radix astragali, followed by precipitation with ethanol. The concentration of copper in extracts was determined by flame atomic absorption spectrometry （FAAS）. The adsorption process of TPA for Cu （ Ⅱ ） was investigated by adsorption equilibrium experiments. Combined with spectral analysis, the interactive mechanism of TPA for Cu （ Ⅱ ） was discussed. The results showed that the adsorption process followed both Langmuir and Freundlich isotherm model, r of which was bigger than 0.99 and 0. 9 respectively. All these suggested that the adsorption process of TPA for Cu （ Ⅱ ） was favorable and nonlinear. Superficial complexation model was predominantly responsible for Cu （ Ⅱ ） uptake. Spectrometry analysis indicated that -- OH and -- NH2 of polysaccharide might be involved in Cu （ Ⅱ ） uptake.