RESUMO
Non-covalent interaction in the binary systems of polyamines (putrescine, spermidine, spermine) with citric acid and complex formation in the binary as well as ternary systems of lanthanide(III) ions, citric acid and polyamine have been investigated. The studies were performed in aqueous solution. The overall stability constants of the complexes were determined using the potentiometric method with computer analysis of the data. Only mononuclear type of complexes were found in the ternary systems and polyamines were located in the outer as well as inner coordination sphere. Non-covalent interaction between biogenic amines and citric acid in the binary and ternary systems were confirmed on the basis of the equilibrium constants analysis and spectroscopic studies.