微波消解－ICP－MS法测定土壤中稀土元素的研究

建立了电感耦合等离子体质谱（ ICP－MS）测定土壤中稀土元素的分析方法。采用HNO3＋HF酸体系用微波消解对土壤样品进行处理，以混合内标（ In、Bi）校正基体干扰和信号漂移，用ICP－MS对其中的16种稀土元素进行了测定。在优化的实验条件下，16种稀土元素标准曲线的相关系数r＞0．9999，检出限为0.012 ng／ml～0.069 ng／ml，加标回收率为84.0％～110％，相对标准偏差（n＝6）RSD均小于3.5％。该方法可用于四种不同类型土壤中稀土元素含量的测定。

Study on Rare Earth Elements in Soil Determined by Microwave Digestion-ICP-MS

The method for determining rare earth elements in soil was established .Soil samples were digested by microwave with HNO3 +HF, and 16 rare earth elements were determined by ICP-MS which mixed internal standard ( In, Bi) to correct the signal drifting.Under the optimized conditions, the correlation coefficient of the calibration were more than 0.999 9, the detection limits of 16 trace elements were in the range of 0.012ng/ml-0.069ng/ml, and recoveries 84.0%~110%, RSD( n=6) less than 3.5%.The method was applied to the determination of rare earth elements in four soil standards .