High Performance Ion Pair Partition Chromatography: The Separation of Biogenic Amines and Their Metabolites

Abstract

Ion pair partition has been combined with high performance liquid-liquid chromatography for the rapid and efficient separation of biogenic amines and their metabolites. These compounds have included catecholamines, serotonin and related amines, and amino acids and carboxylic acids such as dopa, vanilmandelic acid and 5-hydroxyindole-3-acetic acid. The amino compounds and amino acids have been separated as perchlorate ion pairs and the carboxylic acids as ion pairs with tetrabutylammonium ions. Organic solvents such as butanol, ethyl acetate and tributyl phosphate in solution with methylene chloride and hexane have been used as mobile phases, providing high selectivity differences. Using porous silica particles of 10 μ diameter, efficiencies of the order of 2000 plates for 25 cm columns have been generated. The combination of high selectivity and efficiency leads to rapid separations of a relatively large number of components.