RECENT DEVELOPMENTS IN ION-EXCHANGE CHROMATOGRAPHY

By the late 1960s, ion-exchange resins had become ″passe″ since they were widely considered incapable of withstanding the high pressures associated with HPLC without collapsing. The silica-based materials, both pellicular and the more recent totally porous, were able to withstand the rigors of fast flow and high pressure, but lacked the capacity of the organic-based resins. Recent work resulted in both increased capacity of the silica-based material and increased mechanical stability for organic-based materials. Both types share the role of providing ion-exchange capability in HPLC. Exploitation and optimization of either type, however, requires an understanding of the operating principles that govern the performance of both.