CURRENT-EFFICIENT SUPPRESSORS AND METHOD OF USE

摘要

The application relates to a method and device for ion chromatography or pretreatment. In the chromatographic separation stage, ions of an injected sample are eluted through a separation column using an electrolyte as the eluent. In the suppression stage, electrical conductivity of the electrolyte is suppressed but not that of the separated ions so that the latter may be determined by a conductivity cell. The device comprises a self regenerating electrodialytic membrane suppressor (17) with an upstream portion sample stream flow channel defined on both sides by ion exchange membranes (34, 36) flanked by downstream portion ion receiving and source flow channels. In order to increase the current-efficiency without the detrimental effects of excess heat generation, there is provided a lower electrical resistance in the upstream portion compared to the electrical resistance of the downstream portion.