Investigations on the sorption of metal chelates on activated carbon

The mechanism of the adsorption of chelates on activated carbon is discussed. The models used are amino acids and their nickel complexes. It was confirmed that, in general, sorption is quantitative when the chelate contains systems of π-electrons in the molecule and when the centres for binding on carbon and those for the metal ions are spatially separated so that their orbitals do not have a substantial influence. Other factors, e.g., sulphur atoms in the molecule, the length of the chain, and the existence of hydrophobic or hydrophilic groups in the molecule, must also be considered. The sorption of the amino acids was followed spectrophotometrically and that of the nickel complexes by flame a.a.s.