Elevated Temperature Separations on Hybrid Stationary Phases with Low Proportions of Organic Modifier in the Eluent

The properties of two thermally stable organic/inorganic hybrid columns, XTerra MS C₁₈ and XTerra phenyl were examined at elevated temperatures, using a number of test compounds, including acetophenone derivatives and phenols, with 5 and 10% methanol in water as the mobile phases. The thermodynamics of the separations were examined. The study demonstrated that a low proportion of organic modifier and moderate temperatures gave similar separations to higher temperature with superheated water, potentially reducing stress on the column and analytes.