钨、钼中铈、镧的测定方法研究

Measurement Method of Lanthanum and Cerium in Tungsten and Molybdenum

本文以钨、钼中掺杂铈、镧元素为研究对象，提出采用混酸（硫酸一硫酸铵）分解样品，柠檬酸、过氧化氢络合钨基体，采用扣除背景方法，消除光谱干扰，选择适宜的分析条件及仪器工作条件，直接用ICP-AES法测定钨、钼中铈、镧0．0050％～2．0％的含量。考察混酸对试样溶解的影响及最佳量的选择，建立酸分解试样一络合基体钨的分解方法，从而避免了钨酸沉淀析出导致待测元素损失。实验结果表明，采用10mL混酸溶解效果较好，通过优选元素分析谱线、扣除背景方法消除基体光谱干扰，确保了方法的可靠性。元素的检出限从5．7～6．8ng/mL，方法用于钨、钼制品中铈、镧元素的测定，相对标准偏差小于5．41％，回收率在95％以上。测定结果与容量法检测结果一致。

The measurement of the content of cerium and lanthanum elements doped in tungsten and molybdenum were researched. The samples were dissolved in mixed acid （sulfuric acid-ammonium sulfate）. The tungsten matrix was complexed by citric acid and hydrogen peroxide. The method of deducting background was used to eliminate spectral interference. Through choosing suitable analysis conditions and equipment working parameters, cerium and lanthanum contents of 0.005 0%～2.0% in tungsten and molybdenum products were directly determined by ICP-AES method. The effects of mixed acid on the dissolution of the sample and the optimal acid consumption were investigated. The method used for acid decomposing sample-complexing tungsten matrix was established, which can avoid the loss of the measured element caused by the tungsten acid precipitation. The experimental results show that in the case of using 10 mL mixed acid the dissolution effect is better. Through optimizing the analytical spectral line of the element and deducting the background to eliminate the matrix interference spectrum, the reliability of the measurement is ensured. The detection limit of the element is from 5.7～6.8 ng/mL. The method can be used for the determination of lanthanum and cerium content in tungsten