HPLC combined with ICP-MS for the determination of trace amounts of rare earth impurities in high-purity La_2O_3 by using 2-ethylhexyl hydrogen-2-ethylhexylphosphonate resin as a stationary phase

摘要

A new method for the determination of trace rare earth impurities in high-purity La2O3 by HPLC com-bined with ICP-MS is proposed. The chromatographic re-tention behavior of La and Ce in HPLC was studied with 2-ethylhexyl-hydrogen-2-ethylhexylphosphonate (P507) resin as the stationary phase and inorganic acid (HNO3) as the mobile phase. The effects of acidity of the mobile phase, flow rate of eluent and- column oven temperature on the separation of La and Ce were investigated in detail. The results of the effect of different ratios of La / Ce showed that a favorable separation of La and Ce could be obtained easily and rapidly with the method presented. Compared with the conventional open column method, the proposed separation system shows a good performance with regard to short separation time, low reagent consumption, and simple operation. The method has been applied to the analysis of real samples of high-purity La203 with satisfactory results.