Analysis of elemental content and map of beech leaves by PIXE and micro-PIXE

As part of a biomonitoring study of atmospheric particles for the development of a biological and environmental monitoring system in the beech (Fagus crenata Blume) forest ecosystem, we carried out elemental content and two-dimensional analysis of beech leaves by conventional PIXE and micro-PIXE. The beech leaves were collected from natural beech forests at eight locations in Japan. For conventional PIXE analysis of beech leaf samples, 27 elements were determined in total. Mg, P, S, K, Ca, Mn, Fe, Cu and Zn were found to be the important nutrient elements for plants at all sampling sites. According to radar chart analysis results for element (Mg, P, S, K, Ca, Mn, Fe, Cu and Zn) concentrations at each sampling site, K and P, Fe and Ca, and Zn and Cu showed relatively similar patterns. However, elements with a pattern similar to that of Mg, S, and Mn were not found. These elemental concentrations were largely different at beech leaf sampling sites. For micro-PIXE analysis of beech leaf samples from seven sampling sites (Soebetsu beech forest was excluded), scanning transmission ion microscopy (STIM) images and maps of Mg, Si, P, S, K, Ca, Mn and Fe were similar. In samples from Soebetsu beech forest, portions missing from the element distribution were observed. In particular, maps of Mg, Si, P, S, K and Ca were conspicuous. These analysis results may be important information for understanding the mechanism of plant metabolism.