Using XANES to monitor the oxidation state of cobalt complexes.

X-Ray absorption near-edge structure (XANES) spectroscopy was used to monitor the oxidation state of cobalt following treatment of Co-III complexes with reducing agents such as ascorbate and cysteine. It was established that the XANES spectra of mixtures of Co-II and Co-III complexes can be used to calculate proportions of the two oxidation states by monitoring the height of the Co K-edge. The relationships developed were used to estimate proportions of each complex in solutions of Co-III complexes treated with reducing agents. © 2007, CSIRO Publishin