Analysis of Contents and Distribution Patterns of Rare Earth Elements in Surface Sediments of the South Mid_Atlantic Ridge / 分析化学

ABSTRACT

A microwave digestion system was preparation for the digestion of the sediment samples of 16 stations in the Southe mid_Atlantic ridge by using HNO3_H2 O2_HF as the digestion reagent. The rare earth elements ( RE ) in sediments were determined by inductively coupled plasma mass spectrometry, and distribution characteristics of rare earth elements were studied. The microwave digestion_ICP_MS method was used for the determination of rare earth elements with a good linear relationship ( r=0 . 9997-1 . 0000 ) for each element. The detection limit reached ng/L level, the relative standard deviation ( RSD, n=3 ) was less than 3% and the relative error was 6%. The total amount of rare earth elements (ΣRE) in sediment samples from 16 stations varied in the range of 37. 25-134. 77 μg/g, the ratio range of light RE/heavy RE ( LRE/HRE) was 0 . 61-1 . 70 , the average value was 1 . 27 , and the enrichment of light rare earth elements in sediments was slightly obvious. The RE distribution patterns were basically the same in each station with obvious fractionation between LRE and HRE. The RE distribution patterns were also similar in sediments from different sources with slightly difference between terrestrial and marine sediments. The δEu and δCe in the sediments had negative anomaly which showed that the rare earth elements in sediments came from the seawater. This study first analyzed the content and distribution of rare earth elements in the southern Atlantic, providing data and technical support for further study of the distribution of rare earth elements in the Atlantic.