微波密闭消解-等离子体质谱法测定岩石样品中的稀土元素

Determination of Rare Earth Elements in Rock Samples\=by ICPMS Using Microwave Digestion

建立了用微波密闭ＨＦ＋ＨＮＯ３消解样品，等离子体质谱测定岩石样品中１５个稀土元素的分析方法。用该方法对国内外岩石标准样品进行测定，结果表明稀土元素的测定值与标准值之间的相对偏差小于５％，检出限为（０．１～０．９）×１０－９，多次测定结果的相对标准偏差（ＲＳＤ，ｎ＝５）在１．３％～５．２％。各类实际岩石样品中稀土元素的分析结果均与地质规律相符。

A simple method for the determination of rare earth elements (REEs) in rocks by inductively coupled plasma mass spectrometry(ICPMS) has been developed. Rock samples were dissolved using distilled HF+HNO3 in microwave oven. Such a sample digestion process can minimize the contamination and lower the analytical blank and limits of determination. Experimental conditions and the factors affecting the determinations were discussed. The method has been applied to the determination of REEs in the standard reference rock samples. The detection limits of the method for REEs are (0.10.9)10-9. The relative deviations of REE concentration between the determined and certified values in the standard reference rock samples are less than 5% with precision of less than 5.2% RSD (n=5). Simple and straightforward of sample preparation, good accuracy and precision are the remarkable characteristics of this method.\=\=