HR-ICP-MS对黄河甘宁蒙段过滤水和悬浮物中稀土元素含量测定与分馏作用研究

采用高分辨电感耦合等离子质谱(HR-ICP-MS)对黄河甘肃、宁夏、内蒙古段12个采样点过滤水和悬浮物中稀土元素含量进行了测定，并对悬浮物中稀土元素的分馏作用进行了研究。结果表明：过滤水中稀土元素含量较低，含量最高的元素镧(La)浓度仅为32.0 ng·L-1，稀土元素总量平均值为47.5 ng·L-1，以包头磴口(S1)和三湖河口(S2)最高，分别为130.0和100.0 ng·L-1，可能是由外源稀土进入水体所致;悬浮物中稀土元素总量平均值为167.8 mg·kg-1，与中国土壤背景值相近，其中，甘肃什川桥采样点(S11)重稀土元素含量明显高于其他采样点，表明该采样点受到外源重稀土的影响。悬浮物中稀土元素球粒陨石标准化结果与中国土壤分布模式相同，表现为轻稀土元素富集，铕(Eu)中度亏损，铈(Ce)呈现弱的亏损，表明悬浮物中稀土元素主要来源于土壤风化作用。

Study on the Contents and Fractionation of Rare Earth Elements in Filtering Water and Suspensions in Gansu,Ningxia and Inner Mongolia Sections of Yellow River by HR-ICP-MS

In the present paper, high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS) was applied to analyse the contents of rare earth elements (REE) in the filtering water and suspensions from 12 sampling sites in Gansu, Ningxia and Inner Mongolia Sections of Yellow River, and the fractionation of REE in suspensions was also studied. The results demonstrated that the contents of REE in filtering water were very low, and the element with highest content of elements was La(32.0 ng·L-1). The average concentration of total REE (∑REE) in filtering water was 47.5 ng·L-1, and the Baotou-Dengkou (S1) and Sanhuhekou (S2) sampling sites had a higher ∑REE of 130.0 and 100.0 ng·L-1, which implied that there might be external REE sources in the filtering water. And in suspensions, the average content of ∑REE was 167.8 mg·kg-1, which was similar to the Chinese soil background value. While the heavy rare earth elements (HREE) content in Shenchuanqiao (S11) of Gansu province were significantly higher than other stations, which indicated that it might have external HREE sources. The chondrite-normalized patterns of REE in suspensions from the study area were similar to that of Chinese soil, with light rare earth elements enrichment, and moderate Eu depletion and a bit of Ce depletion. It was showed that the contents of REE in suspensions were mainly from soil weathering.