Utilization of Weak Acid-Base Interactions to Improve Separations in Normal Phase Liquid Preparative Chromatography

Abstract

Three 40 μm derivatized silicas, two aminoalkyl and one carboxyalkyl, have been compared to 40 μm silica gel for performance in normal phase preparative liquid chromatography. The three derivatives showed higher selectivity for compounds capable of hydrogen-bond formation or acid-base interactions. Retention times were related to the basicity of the amine bonded derivatives or the acidity of the carboxylic acid derivative and the pK values of the solutes. The advantages for each of the four sorbents for neutral, acidic and basic compounds have been described.