Elemental analysis of soluble and insoluble fractions of river-waters by particle-induced X-ray emission

A procedure has been developed and tested for PIXE analysis of soluble and insoluble constituents in river-water samples. Three kinds of targets were prepared and analyzed with a PIXE system of 3-MeV proton beam. Insoluble components were filtered on a Nuclepore filter of 0.4-μm pores. For soluble fractions, a target of major components was made from a 0.15-ml filtrate evaporated on a user-made polycarbonate film and trace amounts of heavy metals were preconcentrated in a PIXE-target by means of a combination of dibenzyldithiocarbamate-chelation with subsequent condensation into dibenzylidene-D-sorbitol gels. The widespread concentrations (several tenths of ppb to a few tens of ppm) of ∼24 elements from Na to Pb were determined simultaneously in a precision sufficient to reveal the elemental distribution between the soluble and insoluble fractions of river waters. Hence, the methodology can be applied to monitor a pollution problem of rivers.