SIC instrumentation is not limited to reversed-phase separations. It can equally well be used for separations based on ion exchange for assay of cationic and anionic species, since it offers some advantages compared to traditional IC instrumentation.
One example is on-line regeneration of a suppressor cartridge. A downside of packed cartridge-type suppressors is the need to periodically remove the suppressor for regeneration, which places a restriction on the continuous operation of an ion chromatography instrument.
The flow diagram shows how an SIC instrument can be configured to inject when needed a bolus of sulfuric acid, to keep the suppressor cartridge periodically and automatically charged, thus allowing the instrument to operate without interruption for long periods of time. Note that the sulfuric acid does not come in contact with the separation column. The attached document describes in more detail how a Sequential Injection instrument can be optimized for ion chromatography.