Spectrophotometric studies for the effect Of Pb+2 Ion on some chelators

الملخص EN

Lead is one of the toxic heavy metal when presented in a high level over it allowable limit.

To detoxify this heavy metal a chelators were used as in a chelation therapy.

This work studies the complexation of some chelators (EDTA and genistein) with Pb II ion.

A spectrophotometric technique was applied in water and water-ethanol mixture as a solvent, at four different temperatures.

A shift in it max and decrease in absorbance indicating the complex formation.

The stoichiometry of these complexes were determined by a method of the continuous variation (Job's) method, it was found that Pb-EDTA were (1:2), Pb-gensitein (1:1).

These chelator's have a high tendency to complex with Pb II ion which were reflected by its high values of their equilibrium constants.

Thermodynamic parameters indicate a spontaneous interaction (negative free energy change G), and the enthalpy changer for Pb-gensitein complex were positive and Pb-EDTA have negative H which depends on type of the interaction and the structures of the complexes.

The kinetic calculations shows a second order interaction