电感耦合等离子体质谱法测定高纯氧化钆中痕量稀土杂质

Determiantion of Rare Earth Impurities in High Purity Gadolinium Oxide by Inductively Coupled Plasma-Mass Spectrometry

考察了起因于钆基体的多原子离子干扰。当基体浓度为 １ｇ／Ｌ时，基体质谱对相邻 低质量同位素产生严重的峰前沿干扰，基体的多原子离子（ＭＯ＋、ＭＯＨ＋、ＭＨ－）也会对待测 稀土杂质同位素产生严重的谱干扰。研究了Ｇａ、Ｉｎ、Ｉ、Ｃｓ和Ｔ１内标对基体抑制效应的补偿作 用，加入内标元素Ｔ１后，基本上克服了基体效应。建立了高纯氧化钆中１１种稀土杂质氧化物 的 ＩＣＰ－ＭＳ直接测定法。方法的检出限（３σ，ｎ＝１０，积分１ｓ）为 ０．０１２～０．０８８ μｇ／Ｌ，标准加入 回收率为９４．１％～１１７．１％，相对标准偏差（ｎ＝５）为２．１％～８．１％。方法简便、快速、灵敏、精 密度令人满意。

This paper discussed interferences of polyatomic ions originated from the gadolini- um matrix. When the concentration of matrix is at a level of 1 g/L, the matrix mass spectra will seriously interfere with the peak leading edge of the adjacent low mass isotopes. Fur- thermore the ployatomic ions (MO+, MOH+, MH+ ) of matrix interfere spectrometrically with the rare earth impurities to be determined. The method also studied Ga, In, I, Cs and T1 as internal standards to compensate for suppression effect of matrix. After adding the in- ternal standard element Tl, the matrix effect has been basically overcome. A method for the dircet determination of 11 rare earths in highly pure gadolinium oxide by ICP-MS has been established. The detection limit (3σ n= 10, integral time= 1 s) is 0. 012-0. 088 μg/L, the recovery as determined by standard addition is 94. 1 %-117. %, the relative standard devia- tion (n = 5) is 2. 1 %-8. 1 %. This method is simple, rapid and sensitive, and the precision of the method is satisfactory.