Ionic strength effect on liquid chromatographic retention of benzenesulfonates on nonpolar adsorbents

Abstract

Chromatographic retention of substituted benzenesulfonate ions is studied on two nonpolar styrene–divinylbenzene adsorbents as a function of mobile phase ionic strength. On both Amberlite XAD-2 and Hamilton PRP-1, a plot of reciprocal of the capacity factor for each benzenesulfonate versus reciprocal of the square root of ionic strength is linear as predicted by Stern–Gouy–Chapman electrical double layer theory. Chromatographic resolution is improved by using an electrolyte-containing mobile phase.