A NEW LIQUID-CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF ACID DISSOCIATION-CONSTANTS

A new liquid chromatographic method for the determination of acid diss ociation constants is presented on the basis of theoretical equations regarding the effect of background mobile phase ions on the retention of ionic analytes on nonionic polymer packings. The dissociation const ants determined by the present method using Bio-Gel P-2 and Toyopearl HW-40S as the column packings and water as the mobile phase solvent we re in fairly good agreement with the values obtained by potentiometry. This method has an important advantage of permitting the simultaneous determination of the dissociation constants and the charges of analyt e compounds. One can then readily assign a dissociation constant obtai ned for a polybasic acid to the corresponding step of the proton disso ciation.