A bipolar membrane-based cation electrolytic membrane suppressor for ion chromatography.

A bipolar membrane (BPM)-based cation electrolytic membrane suppressor (CEMS) for ion chromatography is described. It has a sandwiched configuration, similar to that of commercial CEMS, except that a BPM and an anion exchange membrane (AEM) are respectively used to isolate the central eluent channel from two outer regenerant chambers. The AEM side of BPM is facing the central channel, contactless with the cathode. The suppression hydroxide ions are generated by enhanced water splitting at the junction layer of BPM. The suppressor showed comparable performance to common one in terms of suppressed background conductivity (∼0.38 μS/cm) and very low noise level (∼0.6 nS/cm). Possible electrochemically induced reductive deamination of AEM when immersed into the alkaline solution at the cathode can be avoided.