交换纤维柱分离ICP-AES测定高纯氧化镱中La、Nd、Eu和Gd

以强酸型离子交换纤维柱分离富集高纯Yb2O3中La,Nd,Eu和Gd等痕量杂质元素,并用Optima5300 DV ICP-AES测定分离富集后的这4种元素。供试纤维对Yb的动态吸附容量为134 mg.g-1,4.0 g纤维柱的分离条件为:pH 3.00的试液以1.0 mL.min-1流速上柱后,分离柱先以流速为1.5 mL.min-1的pH 3.00 HNO3溶液80 mL预淋洗,再以同样流速pH 5.00的0.01 mol.L-1EDTA铵溶液淋洗。结果表明:10 mg Yb与各为0.100μg的La,Nd,Eu和Gd能达到基线分离;分离含100 mg Yb的试液后,在杂质富集液中Yb的残留浓度仅为0.017 1μg.mL-1。研究显示,当待测试液中Yb2O3的浓度小于100μg.mL-1(如Yb 87.8μg.mL-1)时,它对测定La,Nd,Eu和Gd等杂质元素的基体干扰可以忽略不计。富集倍数分别为La2O33.68×105,Nd2O34.20×105,Eu2O33.82×105,Gd2O34.01×105。方法检出限分别为La2O30.005 0 pg.mL-1,Nd2O30.014 pg.mL-1,Eu2O30.001 8 pg.mL-1,Gd2O30.008 2 pg.mL-1。本方法已用于99.99%Yb2O3样品中4种稀土杂质的测定,标准加入的平均回收率分别为La2O394.2%,Nd2O3107%,Eu2O397.8%,Gd2O3102%,RSD(%,n=5)分别为La2O36.2,Nd2O35.9,Eu2O37.3,Gd2O32.5,校正曲线不需进行Yb的基体匹配,分析周期为4 h。

Separation with Ion Exchange Fiber Column and Determination of La,Nd,Eu and Gd in High Purity Ytterbium Oxide by ICP-AES

In the present paper,trace La,Nd,Eu and Gd were separated and enriched with strong acid ion exchange fiber column from high purity Yb_2O_3,and then determined by Optima 5 300 DV ICP-AES.The ion exchange fiber's breakthrough capacity for Yb was 134 mg·g~(-1).The separation condition using 4.0 g fiber column was that after the test solution(ph=3.0)was fed into the ion exchange fiber column at 1.0 mL·min~(-1),the column was pre-leached by dilute nitric acid(Ph=3.00)of 80 mL at 1.5 mL·min~(-1) at first,and then was eluted by 0.01 mol·L~(-1) ammonium EDTA(Ph=5.00)at the same flow rate.The results showed that 10 mg Yb could reach the baseline separation with 0.100 μg of the four rare earth impurities,and after 100 mg Yb in feed solution had been separated,only 0.017 1 μg·mL~(-1) Yb remained in the impurities enriched effluent.When the concentration of Yb_2O_3 is less than 100 μg·mL~(-1)(87.8 μg·mL~(-1) Yb),the matrix interference from Yb on withdetermination of La,Nd,Eu and Gd can be neglected.The enrichment factors were 3.68×10~5 for La_2O_3,4.20×10~5 for Nd_2O_3,3.82×10~5 for Eu_2O_3,and 4.01×10~5 for Gd_2O_3,and the detection limits of the method were 0.005 0,0.014,0.001 8 and 0.008 2 pg ·mL~(-1) for La_2O_3,Nd_2O_3,Eu_2O_3 and Gd_2O_3 respectively.The proposed method was applied to the analysis of 99.99% Yb_2O_3 with RSD(%,n=5)of 6.2,5.9,7.3 and 2.5 for La_2O_3,Nd_2O_3,Eu_2O_3 and Gd_2O_3 respectively,and the average recoveries of standard addition were 94.2%,107%,97.8% and 102% for La_2O_3,Nd_2O_3,Eu_2O_3 and Gd_2O_3 respectively.The calibration curve did not need matrix matching with Yb,and the analysis period was within 4 hour.