Effect of temperature (5 degrees-65 degrees C) on the separation of 11 inorganic anions by ion interaction chromatography (IIC) was studied employing RP C-18 and C (PhenylHexyl) columns and aqueous mobile phase: 2.8mM NaHCO3+0.7mM TBAOH (tetra-n-butylammonium hydroxide). The apparent enthalpy changes, H for hydrophobic ions like I-, SCN-, and ClO4 (-) largely exceeded 3 kcal/mole suggesting that added to ion exchange they are retained by hydrophobic adsorption. Unlike conventional strongly basic anion exchangers, our system can be used at elevated temperatures with alkaline eluents without irreversible damaging the column.