Paper ionophoretic technique in the study of biologically important beryllium(II) / cobalt(II)-homoserine binary complexes in solution

Abstract

Quantitative indication of the process of forming a complex comes from the evaluation of the stability constants, which characterize the equilibria corresponding to the successive addition of ligands. A method, involving the use of paper electrophoretic technique is described for the study of binary complex system in solution. Present method is based upon the migration of a spot of metal ions on a paper strip at different pH’s of background electrolyte. A graph of pH against mobility gives information about the binary complexes and permits calculation of their stability constants. The first and second stability constants of [Be(II)-homoserine] and [Co(II)-homoserine] complexes were found to be (7.13 ± 0.02; 6.11 ± 0.09) and (4.27 ± 0.07; 3.47 ± 0.11) (logarithm stability constant values) for Be(II) and Co(II) complexes, respectively, at ionic strength of 0.1 mol/L and a temperature of 35 °C.