Application of Mixed-Mode HPLC Columns to Samples Containing Ionic and Hydrophobic Analytes

This application note presents the applications of mixed-mode ion-exchange HPLC columns and discusses the separation principles of the columns. Using Dionex’s UltiMate^® 3000 Separation System, an anion-exchange mixed mode column was used to separate and quantify the anti-corrosion components of engine coolants, a mixture of acids and neutral organic compounds, and additives to carbonated beverages, including sweeteners and preservatives. A cation-exchange mixed mode column was also used to determine melamine in milk-products as both a primary and confirmatory method. Also, this column was used to monitor folic acid synthesis. This presentation will discuss the separation principles of these columns and how the above applications were developed.