利用微波等离子体炬四极杆质谱在线测定稀土矿样中的多种稀土元素

Direct Determination of Rare Earth Elements in REE Ores Using Microwave Plasma Torch Coupled with Quadrupole Mass Spectrometry

随着稀土的应用越来越广泛,开发稀土元素的快速在线检测技术已日趋成为行业发展的需求。本文以微波等离子体炬（MPT）为离子源,以四极杆质谱仪（QMS）作为质量分析器建立了一种快速、直接检测水样中稀土元素的质谱检测方法,并将其应用于分析稀土矿样中的多种稀土元素。研究表明,应用MPT-QMS测定水样中的钇、镧、铈、钕、铕五种稀土元素,检出限（LOD）可达11.0-60.5μg/L,测定范围为50-1000μg/L。当分析固体稀土矿样时,样品经酸溶处理后通过气动雾化形成气溶胶,再进行冷却干燥,气溶胶由MPT的中心管道进入等离子体中,产生稀土元素复合离子,再引入QMS中进行分析,即可以定量地测定矿样中稀土元素的含量。同一样品用电感耦合等离子体质谱（ICP-MS）进行对比实验,两者的检测结果在数量级上接近,证明了MPTQMS方法在半定量的意义下是准确、可靠的,因而这种快速的检测方法可发展成为水体中金属元素的现场分析方法,应用于环境水、生活水质量在线监测等领域。

With the widespread application of rare earth elements analysis, the development of rapid detection technology of rare earth elements has increasingly become a necessity within the industry. Microwave Plasma Torch （MPT ） as the ion source and Quadrupole Mass Spectrometry （ QMS） as the mass analyzer to develop a method for fast detection of rare earth elements （ REEs） in water and ore samples has been developed and discussed in this paper. With the MPT-QMS method, for elements Y,La, Ce, Nd, Eu in water samples, the limits of detection （LODs） are 11.0 -60. 5 μg/L, and the linear ranges are 50 - 1000 μg/L. When analyzing ore samples, the samples were firstly digested by acid solution and the sample solution formed an aerosol, which was then cooled to keep it dry. The aerosol entered the plasma by the centre tube of the MPT and formed REE ions. These ions enter the QMS, and concentrations of REE elements can be quantitatively determined. Repeated analyses of the same sample by Inductively Coupled Plasma-Mass Spectrometry （ ICP-MS） yield similar results, indicating that the semi-quantitative analyses of MPT-QMS are precise and reliable. Therefore,MPT coupled with QMS is suitable for portable, rapid analysis of metal elements in water and can be used in the field of in situ quality monitoring of environmental and drinking water.