Trace Metal Complexation in High Ligand Variety Natural Media

A relatively small variety of ligand number two, three, and four complexes is sufficient to generate a very large number of mixed-ligand species. A simple model is presented which quantitatively accounts for the sum complexation intensity due to very large numbers of mixed-ligand complexes. Mixed-ligand complexes can dominate the solution chemistry of trace metals in ligand-rich, high ligand variety media. A probable consequence of neglecting mixed-ligand complexation in high ligand variety systems is substantial underestimation of a metal's degree of complexation.