电镜-能谱仪在柳树叶重金属污染研究中的应用

采用自然干燥、化学处理、冷冻处理3种方法制备待测样本,运用扫描电镜和透射电镜结合X射线能谱仪研究柳树叶肉组织对重金属的累积状况,并定位到栅栏组织的细胞壁,为定性定量以及定位分析组织细胞固定、转移重金属污染探索合适的制样方法.结果表明:(1)重金属Pb、Cu、Cd、Zn在柳树叶肉组织被检测到,并已进入到细胞壁内,同时定量结果显示污染越严重,重金属累积量越多,证明了柳树叶对重金属污染的吸收能力;(2)通过综合比较,认为冷冻处理的样本比较适合进行植物组织微区的元素定性定量以及定位分析,因此推测冷冻制样加冷冻电镜的方法将会最为理想.

Application of EM-EDS in Research on Willow Leaves Absorbing Heavy Metal Pollution

The absorbing activity of willow leaves for heavy metal pollution was studied by scanning electron microscopy(SEM), transmission electron microscopy(TEM) and energy dispersive spectrometry(EDS) using 3 different sample preparation methods including natural drying, chemical treatment and freezing treatment. The tested willows were obtained from different regions. The whole mesophyll tissue was studied and also the cell walls in palisade tissue. A suitable method can be acquired for qualitative, quantitative and positioning analysis of some heavy metal elements in tissue and cells by this exploration and comparation. A result showed that Pb, Cu, Cd and Zn were detected in willow mesophyll tissue even in cell walls of palisade tissue. And the quantitative data indicated that the more serious the pollution is the more heavy metals accumulat. So the absorbing activity of willow leaves for heavy metals was proved by this experiment. The freezing treatment was suitable for the qualitative, quantitative and positioning analysis elements by electron microscopy(EM)and energy dispersive spectrometry(EDS) through comprehensive comparison. So it is speculated that frozen sample preparation and cryo EM with EDS is the most ideal method.