Comparison of in-vacuum micro-PIXE and in-air micro-PIXE for unfixed plant sample

PIXE analysis is very useful for the simultaneous determination of various elements. Typically, when micro-PIXE analysis of biological samples with high water content is performed in a vacuum, freeze-drying methods are used to fix the structure and remove any ice crystals present in a controlled manner to prevent changes or redistribution of elemental content in the sample. This method is essential for cell size analysis. However, we considered that fixation is not always necessary for macroscopic analysis of plant tissue size. Therefore, we investigated the extent to which elemental density changes with vacuum extraction from elemental density ratios obtained from micro-PIXE analysis of Arabidopsis thaliana leaves in-air and in-vacuum. The deformation caused by beam irradiation and the quantitative changes of C, O, and H in the samples were also evaluated by STIM and RBS analyses of Arabidopsis thaliana petal.