IC Workshop: Suppressor Selection and Use

Ever since the introduction of ion chromatography (IC) in 1975, suppressor devices are used in combination with conductivity detection to chemically reduce the background conductance of the electrolyte used as the eluent, while at the same time enhancing analyte conductivity and thus increasing sensitivity. Although this sensitivity increase is the primary advantage of the suppression technique in comparison with nonsuppressed conductivity detection, selectivity is also increased, because chemical modification of eluent and analytes turns the conductivity detector from a bulk-property detector into a solute-specific one. The use of high-capacity ion exchangers requiring a much higher electrolytic strength in the mobile phase as well as the hyphenation of IC with mass spectrometry are not feasible without the use of suppressor systems. 

The type of suppressor devices has changed significantly over the past four decades, starting with periodically regenerated suppressor columns in the original embodiment of IC all the way to continuously regenerated, membrane-based devices that are predominantly used today. Thermo Fisher Scientific currently offers a whole portfolio of chemically and electrolytically operated suppressor devices that are specifically designed for various applications. The scope of this workshop is to give some guidelines for selecting the right suppressor for a given application together with recommendations for their proper use.