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 u sing proton induced X-ray emission (PIXE), instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS), tot al organic carbon (TOC) analysis and photon correlation spectroscopy (PCS) are associated to follow the repartition of metallic trace elements associa ted with humic acids (HA) colloids of different sizes. This paper illustrat es the innovative character and the capabilities of these complementary tec hniques and confirms the associations between HA and numerous trace element s (both cations and anions), and evidences a strong affinity of the smalles t colloids (<15 nm) for these elements. (C) 2001 Elsevier Science B.V. All rights reserved.