Keith A. Friedman

New membrane-based electrolytic suppressor device for suppressed conductivity detection in ion chromatography

Abstract This paper discusses the newest advancement in chemical suppression preceding conductivity detection. The new suppressor uses electrolysis of deionized water to generate the required acid or base for the suppression neutralization reaction and utilizes the electrical field to enhance, through electrodialysis, the suppressors capacity for neutralization. The suppressor is able to accommodate eluents as high as 150 mM NaOH, without the need for a separate regenerant solution, by recycling the conductivity detector cell waste to the regenerant and electrolysing the water in the waste stream to the required acid or base. The device is able to use deionized water as regenerant and neutralize the eluent stream to deionized water without the expected increase in resistance by employing ion exchange material in intimate contact with the electrodes and the membranes. The current is carried with low resistance through the ion-exchange material via ion transport from one ion-exchange site to another.