“…Humic acids and fulvic acids form stable complexes with lead (II) ions and other metal ions; these complexes may be separated from a mixture of humic acid or fulvic acid metal complexes by gel permeation chromatography (Miicke and Kleist, 1965;KlOcking and Miicke, 1969). Therefore, it should be possible to isolate intact, humicmetal complexes from soils and sediments.…”