Study of the repartition of metallic trace elements in humic acids colloids: potentialities of nuclear microprobe and complementary techniques

Techniques of solid and solution investigation such as nuclear microprobe using proton induced X-ray emission (PIXE), instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS), total organic carbon (TOC) analysis and photon correlation spectroscopy (PCS) are associated to follow the repartition of metallic trace elements associated with humic acids (HA) colloids of different sizes. This paper illustrates the innovative character and the capabilities of these complementary techniques and confirms the associations between HA and numerous trace elements (both cations and anions), and evidences a strong affinity of the smallest colloids (<15nm) for these elements.