| Abstract: | The separation of isomers of polystyrene oligomers was demonstrated on a carbon‐clad zirconia stationary phase in an acetonitrile mobile phase. The carbon‐clad zirconia surface gave considerably better resolution of isomers than a C18 surface, and the separation was sensitive to the end group of the oligomer. Oligomers with sec‐butyl end groups displayed almost twice as many isomers as the corresponding n‐butyl oligomer on the carbon‐clad zirconia surface. These additional bands could be explained by the stereochemistry of the sec‐butyl end group. In addition, the migration rate of the polystyrene isomers was dependent upon the end group, with n‐butyl polystyrenes displaying significantly greater retention on the carbon‐clad zirconia stationary phase. In comparison, the selectivity of conventional C18 columns could not discriminate between the n‐butyl and sec‐butyl end groups. |
