中子活化分析法研究蕨类植物中稀土元素的分布特征  

Study on contents and distribution characteristics of REE in fern by NAA

作　　者：肖海清[1] 张智勇[1] 李福亮[1] 柴之芳[1] 

机构地区：[1]中国科学院核分析技术重点实验室中国科学院高能物理研究所,北京100039

出　　处：《核技术》2003年第6期420-424,共5页Nuclear Techniques

基　　金：国家自然科学基金重点项目(19935020);中国科学院重要方向性项目资助

摘　　要：用中子活化分析(NAA)方法测定了11种蕨类植物中8个稀土元素(La、Ce、Nd、Sm、Eu、Tb、Yb和Lu)的含量,并研究了稀土元素(REE)在植物体内的分布特征。结果显示,蕨类植物叶中的稀土含量普遍较高。对于采自植物体不同部位的叶子,叶子越老,稀土元素含量越高。经球粒陨石归一化后,发现稀土元素分布模式主要是由母土性质决定的。然而,在植物从土壤吸收及输送过程中,稀土元素发生了某些不同程度的分异现象,分布模式曲线表现出与母土有明显的差异。如土壤中轻重稀土比为9.4,而芒萁叶中轻重稀土比为24—51,表明重稀土不易被植物体吸收输运。Concentrations of 8 REEs (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) in fern and their host soil, collected from the south China, have been determined by INAA. The chondrite-normalized REE patterns for different plants and different parts of Dicranopteris dichotoma and their host soil were studied. The results showed that the older the leaves are, the higher the concentration levels of REE are. Particularly, leaves of the fern (Dicranopteris dichotoma) contained extremely high concentration of the total REE(332—3411 礸/g). Generally, the REE distribution pattern in each sort of plant was very similar and reflected the characteristics of their host soil. However, the chon-drite-normalized REE patterns in some plants relative to the host soils exhibited obvious fractionation, such as the de-pletion of the heavy REE in leaves of the fern species, Dicranopteris dichotoma.

关 键 词：稀土 中子活化分析 蕨类植物 

分 类 号：O657.4[理学—分析化学] O614.33[理学—化学]