Sorption of pyridine-3-carboxylic acid and silver(I) from multicomponent aqueous solutions with Dowex-50 sulfonic cation exchange resin

The equilibrium distribution of pyridine-3-carboxylic acid, silver(I) ions, and protons between aqueous solutions and Dowex-50 sulfonic cation exchange resin was studied. The counter-ion composition of the cation exchange resin was determined by solving a system of equations for binary ion exchange selectivity coefficients and the mass balance equation. According to FT IR and CPMAS 13C NMR spectroscopy of solid samples, pyridine-3-carboxylic acid exists in the Dowex-50 phase as [H2L]+ cations. High distribution constants indicate that pyridine-3-carboxylic acid and silver can be concentrated in the polymer phase.