Applications of NAA, PIXE and XPS for the quantification and characterization of the humic substances/iodine association

This paper illustrates the coupling of Neutron Activation Analysis (NAA), P roton Induced X-ray Emission (PIXE) and X-ray Photoelectron Spectroscopy (X PS) to quantify iodine contents in natural humic substances from different geochemical origins and to determine its chemical environment. Non negligib le contents of iodine from some hundreds of mug/g to more than one weight p er cent have been quantified in the humic substances, and iodine seems to b e attached to the organic matter by covalent bonds.