中文摘要：

针对目前最常用的液-液萃取、ICP-MS测定法检测表生水体中微量稀土元素方法,研究了不同pH值条件下,酸性膦（65%HDEHP和35%H2MEHP）自表生水体中萃取稀土元素（REEs）的回收率。结果表明,在pH1-4的范围内,不同性质的水体（湖泊、河流、地下水）有不同的REEs回收率。其中湖水在pH 1.8-3.7有90%以上的回收率,最高回收率为93.64%;河水在pH 2.1-3.5范围内有90%以上的回收率,最高回收率为95.52%;地下水仅在pH 1.3-1.5时回收率超过90%,最高回收率为97.61%。说明在萃取不同表生水体中稀土元素时,需要调到特定的pH值才能得到最好的萃取效果。

英文摘要：

The method for the analysis of dissolved rare earth elements （REEs） by inductively coupled plasma mass spectrometry （ICP-MS） in surface waters after preconcenration with solvent extraction and back-extraction has been used widely. Extraction efficiency of REEs from surface waters by the mixture of 65 % HDEHP and 35 % H2 MEHP was studied under different pH condition. The result shows that the recoveries of REEs are very different for different surface waters （lakes, rivers, and groundwater） in the range of pH from 1 to 4, with the main values 60% -90%. The highest recovery of lake water is 93.64% at pH about 1.6; the highest recovery of river water is 95. 52 % at pH about 3.0; the highest recovery of groundwater is 97.61% at pH about 1.4. It is concluded that different pH are needed when extraction REEs from different surface waters for getting best recovery.