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.