离子交换树脂光度法测定牧草中稀土总量

Ion-Exchange Resin Phase Spectrophotometry for Determination of Trace Rare Earth in Herbage

用离子交换比色法￣［３，４］直接测定牧草中稀土总量，把形成的ＴＢＡ－稀土络合物富集在强碱性的阴离子交换树脂上￣［４］，显色与高倍率浓集同时进行，具有比溶液光度法更高的灵敏度．对ＴＢＡ－稀土络合物形成的最佳条件作了较详细的研究．

n the medium of HCl,rare earth forms binary complex with tribromoarsenazo(TBA)whichcan be absorbed by the strong basic anibn resin. And this resin phase can be used for the deter-mintion of the trace Rare Earth in herbage. The analytical results are satisfactory.The Beer's lawis obeyed in the range f 0～15μg/250ml for the determination of rare earth.