Application of PIXE analysis to environmental samples stable element distribution in sea algae by scanning microprobe analysis

The resolution of a 33+-3 μm microprobe focussed with quadrupole doublet installed at the 3 MV Van de Graaff of the National Institute of Radiological Sciences, Japan, was used for the present analysis. Brown algae, Hizikia fusiforme was the sample target bombarded with a 2 MeV proton beam collimated mechanically into a rectangular image of 100 μm x 700 μm. Scanning across the sample target prepared into a longitudinal section from the caulis of the algae provided the following observations. More than 12 elements such as Al, Si, P, Cl, Ca, Mn, Fe, Cu, Zn, As, Br and Sr were determined simultaneously, together with their distributional information across the diameter. In the medullary layer, Mn and Zn were specific in their accumulation, while the deposition of Fe, Cu, As and Br were observed to be high in the epithelial layer, especially Fe and Cu which were found on the surface, where they contacted ambient sea water, but no significant change in pattern was indicated for such elements as Al, P and Cl. The PIXE microprobe analysis was, therefore, effective in its detectability for elements below a few ppm level, resultantly providing further possibilities for collecting information from bio-medical and environmental samples on trace characterization of elements. (author)