Elementos complejos orgánicos (pdf)

Dissolved organic matter in oceanic waters was investigated in terms ofthe interaction with copper. Three classes of organic ligands, namely, L₁, L₂ and LN that were concentrated by repeated rounds oflyophilization and dialysis, were distinguished from each other by differences in their complexing abilities for copper. Ligands L₁ and L₂ appeared to be assigned to the group ofweak ligands in the literature. The conditional stability constant of ligand LN for Cu(II) was extremely high and was comparable to that ofEDTA (ethylenediaminetetraacetic acid).
Two types of ligands that were similar to weak ligands L₁ and L₂, were extracted directly from seawater using immobilized metal ion affinity chromatography (IMAC). lMAC gave a new insight in that the weak ligands were a mixture of at least two types of different organo-chemicalligands and that their dynamics might be active in the water column.