Effect of polystyrene-divinylbenzene resin sulfonation on solute retention in high-performance liquid chromatography

Polystyrene-divinylbenzene (PS-DVB) resins were sulfonated under different conditions to give a series of resins with sulfonic acid capacities ranging from 0.27 to 2.63 mmol/g. Each of the resins was packed into a conventional column and used for HPLC separation of various substituted benzenes using acetonitrile-water solutions as the mobile phase. In a mobile phase of acetonitrile-water (30:70), a nearly linear decrease in retention factor with increasing sulfonic acid capacity was noted for a set of substituted benzenes (polar and non-polar). The retention factors at the highest sulfonic acid capacity studied (2.63 mmol/g) were only 0.10 to 0.16 that of the unsulfonated resin. The sulfonated resins were also used for quasi-normal-phase separations of polar analytes such as glycols and sugars. In binary acetonitrile-water mobile phases, retention factors increased in a regular fashion as the concentration of acetonitrile was increased from 70 to 95%. Retention factors of the same analytes also increased substantially with increases in sulfonic acid content of the resin. (C) 1998 Elsevier Science B.V.