萃取色谱分离 - 电感耦合等离子体质谱法测定高纯氧化铽中痕量稀土杂质的研究

Determination of Rare Earth Impurities in High Purity Tb_4O_7 by ICPMS with P507 Extraction Chromatography

考察了源于基体Ｔｂ的多原子离子质谱干扰及基体Ｔｂ对稀土杂质测定信号的影响，研究了Ｐ５０７ＨＣｌ萃取色谱体系分离高纯Ｔｂ４Ｏ７基体与痕量稀土杂质的条件，采用Ｒｅ内标补偿直接测定与分离基体后测定相结合的方式，建立了分析高纯Ｔｂ４Ｏ７中痕量稀土杂质的电感耦合等离子体质谱（ＩＣＰＭＳ）法，检出限为５～２１ｎｇ／Ｌ，加标回收率为９０％～１０９％，３次测量的相对标准偏差为１．３％～６．５％，分离周期近９ｈ。方法可用于纯度（质量分数，ｗ）为９９．９９％～９９．９９９９％的Ｔｂ４Ｏ７中痕量稀土杂质的分析。

The matrix effect of Tb_4O_7 on signals of rare earth impurities and the mass spectra interferences originated from polyatomic ions of Tb_4O_7 were studied. The optimum conditions for separation of Tb_4O_7 and rare earth impurities by 2-ethylhexyl hydrogen2-ethylhexylphosphonate (P507) extraction chromatography were investigated. A method was developed for the determination of rare earth impurities in high purity Tb_4O_7 by ICPMS, based on the combination of direct determination and determination after separation . The detection limits for REEs were 5～21 ng/L. The recoveries of REEs for spiked samples were 90%～109% with the precision of 1.3%～6.5% RSD( n =3). The method can be applied to the analysis of 99.99%～99.9999% high purity Tb_4O_7.