Quaternized trimethylaminated polystyrene-coated zirconia as a strong anion exchange material for HPLC

The synthesis and characterization of a new, base-stable, strong anion exchange phase by amination of polystyrene-coated zirconia (PS-ZrO2) are described. Even though the ion exchange capacity of the quaternized trimethylaminated PSZrO2 (QTMA-PS-ZrO2) is only 0.07 mequiv/g, it is able to separate various inorganic anions, benzoic acid derivatives, and nucleotides in their deprotonated states. The effects of ionic strength, eluent pH, and counterion type are discussed. In the presence of both phosphate and fluoride ions in the eluent, band broadening caused by Lewis acid/base interactions between zirconia and analytes is greatly suppressed. The mixed retention modes (ion exchange, hydrophobic interaction, and Lewis acid/base interactions) on QTMA-PS-ZrO2 offer a different selectivity toward various anionic analytes than do other zirconia- and nonzirconia-based ion exchangers.