Analytical results of REE in practical samples.

The polymetallic mineral samples in Pan-Xi region are rich in rare earth resources, and exploring an efficient and accurate analysis method is of great significance for their comprehensive utilization. In this study, the samples were decomposed by three methods, namely closed acid dissolution, open acid dissolution with five acid and alkali fusion with sodium peroxide, and the 15 REE were determined by inductively coupled plasma mass spectrometry (ICP-MS) with Rh and Re as internal standard correction elements. The comparative experiments were conducted using standard substances, and the results showed: (1) The detection limit of closed acid dissolution method was low with relative standard deviation (RSD) ranging from 2.51% to 9.56% and the accuracy of method (ΔlgC) ranging from 0.006 to 0.073, while the sample processing was long, and the results of some REE were low. (2) The RSD of open acid dissolution with five acid method ranged from 1.93% to 7.96%, and ΔlgC ranged from 0.004 to 0.045 with low results of the determination results of REE. (3) The alkali fusion with sodium peroxide method eliminated the influence of matrix effects by selecting instrument optimization, sample dilution, appropriate internal standard elements, etc. The RSD ranged from 1.24% to 6.49%, and ΔlgC ranged from 0.001 to 0.032. In conclusion, alkali fusion with sodium peroxide method has a fast analysis process, complete sample dissolution, and the accuracy and precision of test results can meet the requirements of specification (DZ/T0011-2015), which is most suitable for the analysis of REE in polymetallic mineral samples from Pan-Xi region.

潘西地区多金属矿物样本富含稀土资源，探索一种高效精确的分析方法对于其综合开发利用具有重要意义。本研究中，样本通过三种方法进行分解，即密闭酸溶、开放酸溶（五酸）及过氧化钠熔融，并采用电感耦合等离子体质谱法（ICP-MS）以Rh和Re作为内标校正元素测定15种稀土元素。通过标准物质进行的比较实验结果显示：（1）密闭酸溶方法的检测限低，相对标准偏差（RSD）介于2.51%至9.56%之间，方法的准确性（ΔlgC）介于0.006至0.073之间，但样品处理时间长，部分稀土元素的检测结果较低。（2）开放酸溶（五酸）方法的RSD介于1.93%至7.96%之间，ΔlgC介于0.004至0.045之间，稀土元素测定结果较低。（3）过氧化钠熔融方法通过仪器优化、样品稀释、选择适当的内标元素等措施消除了基质效应的影响，RSD介于1.24%至6.49%之间，ΔlgC介于0.001至0.032之间。综上所述，过氧化钠熔融方法具有快速的分析过程、完全的样品溶解，且测试结果的准确性与精确度符合规范（DZ/T0011-2015）的要求，是最适合分析潘西地区多金属矿物样本中稀土元素的方法。