HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC STUDY OF THE RETENTION AND SORPTION OF SULFAS ON POROUS COPOLYMERS

Conditions for the sorption of sulfas on XAD-2 and XAD-7 co-polymers are evaluated. Increasing the concentration of the organic solvent in the organic solvent-water eluting mixture decreases the sorption. As pH is increased, the sorption passes through a maxima, which is typical of ampholytes that are not zwitterions. The degree of sorption at the maxima is influenced by the ionization constants and the structure of the side R group. It appears that the latter plays the major role in the interaction with the stationary phase. Retention as a function of pH can be quantitatively described by considering the protonic equilibria. Several typical separations are illustrated. © 1979, Oxford University Press. All rights reserved.