Detection, characterization and dynamics of dissolved organic ligands in oceanic waters

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.