普里兹湾沉积物中稀土元素的测定及其配分模式分析

以HNO₃-H₂O₂-HF为消解体系，采用微波法对沉积物样品进行消解处理，利用电感耦合等离子质谱法测定了普里兹湾(Prydz Bay)沉积物中Sc, Y, La, Ce, Pr, Nd, Sm等16种稀土元素(rare earth elements，REEs)的含量，并进行了配分模式分析。从普里兹湾沉积物样品的分析数据和球粒陨石标准化配分模式可以看出：稀土总量(∑REEs)变化范围为117.35～348.63 μg·g-1，其中Ce含量较高，在总量中占了很大比例;各站位平均值为196.75 μg·g-1，总量最大值是最小值的2.97倍;各个站位稀土元素分布模式基本一致，轻重稀土元素之间有明显的分馏。该方法表明：各元素的线性关系良好，相关系数≥0.999 7;相对标准偏差(RSD)＜5.0%，相对误差＜10.0%;除了Sc的检出限稍高，其他元素的检出限均能达到ng·L-1。因此，该方法适用于沉积物中稀土元素的定量分析。

Determination and Distribution Patterns Analysis of Rare Earth Elements in Sediments of Prydz Bay

A sensitive quantificational method was developed for the analysis of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, etc. in sediments of Prydz Bay by inductively coupled plasma mass spectrometry, and then the REE distribution patterns were analyzed. The samples were digested by microwave using HNO₃-H₂O₂-HF as oxidant. The results showed that the total contents of rare earth elements in eight sites ranged from 117.35 to 348.63 μg·g-1 and the maximum value was 2.97 times of the minimum value. The REE distribution patterns of different sites in sediments were basically identical and there was an obvious fractionation between LREEs and HREEs. The linear correlation of the method was preferable (r=0.999 7～1.000 0). The RSDs (n=3) were no more than 5.0%, and the relative errors were no more than 10%. The detection limits of rare earth elements reached ng·L-1 level except for Sc. This method was suitable for the analysis of REEs in sediments with the advantages of rapidness, simplicity, high precision and accuracy.