Determination of pharmaceutically related compounds by suppressed ion chromatography: III. Role of electrolytic suppressor design

► New high capacity IC suppressors have been evaluated. ► Reduced interactions with hydrophobic analytes were observed. ► Analyte peak shapes after suppression were improved. ► Analyte recoveries of 95–99% were observed after suppression. For the hyphenation of ion chromatography to nebulising detectors or mass spectrometry, suppression of the non-volatile ionic eluent to water is a required step to avoid elevated detector baselines. Presented here is a study of three new designs of electrolytic suppressors, incorporating high ion-exchange capacity screens and high ion-exchange capacity membranes in different thickness and compositions. These designs aim to minimise hydrophobic interactions of the suppressor with organic analytes and to provide higher compatibility with eluents containing acetonitrile. In comparison with a commercially available electrolytic suppressor and also a commercially available chemical suppressor, the new high-capacity suppressor showed superior performance, exhibiting minimal interactions with a test set of analytes under the examined conditions. This led to the attainment of high recoveries of the analytes after suppression (93–99% recovery) and significantly reduced band broadening during suppression. The new suppressor has been shown to perform well under both isocratic and gradient elution conditions.