To
investigate the chemical speciation of metals, we are using an
analytical multi-method approach relying on electrochemistry,
electron microscopy, and X-ray absorption
spectroscopy. These complementary techniques allow us
respectively to determine the truly dissolved metal fraction as
well as the presence, concentrations, and conditional stability
constants of dissolved ligands; probe elemental
associations at the nano-scale; and establish the
coordination and the valence state of the metal using direct
methods.
Micrograph showing natural
Fe oxides that form on natural organic matter fibrils