Iodination of humic acid samples from different origins

Abstract

The iodination of Gorleben and synthetic humic substances (HS) was studied complementarily by UV-visible and X-ray Photoelectron Spectroscopy (XPS). The I 2 (aq) consumption kinetics could neither be linearly correlated to [H + ] nor to HS concentration as already observed in the literature. Nevertheless, the electrophilic substitution mechanism was further evidenced by the production of both I 3 - and I - , leading to a covalent bonding. The XPS analysis of the iodinated samples confirmed the covalent bonding between iodine and carbon of HS for all the samples.