Comparison of Silica-Based Strong Ion Exchangers and Low-Capacity Polymer-Based Strong Ion Exchangers For the Separation of Organic Analyte Ions Using Indirect Uv Detection

Abstract

Abstract The retention and separation of organic analyte anions and cations was studied on two different types of columns; low-capacity polymer-based ion exchangers and silica-based strong ion exchangers. It was found that separations and elution orders were different between the two columns. the retention of an organic analyte ion on a particular stationary phase was dependant on the type of retention mechanism by which the analyte ion was retained: adsorption, ion exchange or a combination of the two. the low-capacity ion exchanger provides both adsorption sites and ion exchange sites with which the organic analyte ions may interact. Organic analyte ions are retained on the silica-based ion exchangers predominantly by ion exchange. the mobile phase variables that were found to affect analyte ion retention were: ionic strength, concentration of UV-active counterion, mobile phase pH, and concentration of organic modifier. A comparison is done on the retention data and elution orders that were found for the organic analyte ions on the silica-based strong ion exchangers and the low-capacity ion exchangers.