REE bound polysaccharides in leaves of Dicranopteris dichotoma by MAA

The binding of REEs with polysaccharides (PSs) in the leaves of fern Dicranopteris dichotoma (DD) has been studied by molecular activation analysis (MAA). The PSs of different solubilities in the leaves of DD, which were named cold-water-soluble, hot-water-soluble, acidic-soluble and basic-soluble PSs, were obtained using biochemical separation techniques. After deproteinization and gel permeation chromatography separation, the absorption curves of the PSs were obtained by colorimetry. The eight REEs (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) were also detected in the PSs by neutron activation analysis (NAA). The results obtained showed that the REEs were bound firmly with the PSs in the leaves of DD. The molecular weight measurement on Sephadex G-200 demonstrated that those PSs bound with REEs were mostly small molecular weight polysaccharides (10 000 to 20 000 u).