沉淀分离-电感耦合等离子体原子发射光谱法测定稀土钨电极中镧铈钇

准确测定稀土钨电极中稀土元素的含量,对于研究产品理化性能、把控产品质量、推动产品性能升级等具有积极意义。实验采用3.0mL氢氟酸-2.0mL硝酸溶解样品,经高氯酸冒烟,将大部分基体以钨酸(H₂WO₄)形式析出,加快反应速度的同时避免了基体对稀土元素测定的干扰。选择La 333.7nm、Ce 418.6nm、Y 360.0nm为分析谱线,采用电感耦合等离子体原子发射光谱法(ICP-AES)测定稀土钨电极中镧、铈、钇配分含量。校准曲线线性相关系数均大于0.999 9,方法检出限为0.003%～0.006%。按照实验方法测定稀土钨电极实际样品,结果的相对标准偏差(RSD,n=7)为1.5%～3.2%,加标回收率为98%～101%。

Determination of lanthanum,cerium and yttrium in rare-earth tungsten electrode by inductively coupled plasma atomic emission spectrometry with precipitation separation

It had positive effects for accurate determination of rare-earth elements in rare-earth tungsten electrode on the investigation of product physical and chemical peoperties, the control of product quality and the promotion of product performance upgrading. The sample was decomposed with 3.0mL of hydrofluoric acid and 2.0mL of nitric acid. After perchloric acid fuming, most of the matrix was precipitated in the form of tungstic acid (H₂WO₄), which accelerated the reaction speed and meanwhile avoided the interference of matrix with determination of rare-earth element. La 333.7nm, Ce 418.6nm and Y 360.0nm were selected as the analytical lines. The contents of lanthanum, cerium and yttrium in rare-earth tungsten electrode were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The linear correlation coefficients of calibration curves were all higher than 0.9999. The limits of detection were between 0.003% and 0.006%. The proposed method was applied for the determination of rare-earth tungsten electrode actual sample. The relative standard deviation (RSD, n=7) of determination results were between 1.5% and 3.2%, and the recoveries were between 98% and 101%.