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CES 300 Capillary Electrolytic Suppressor

Capillary Electrolytic Suppressor (CES™ 300) for Capillary IC Analysis

The CES 300 Capillary Electrolytic Suppressors are optimized for eluent flow rates typically seen in capillary systems
(5 – 30 µL/min). When used for anion analysis, the ACES 300 converts highly conductive hydroxide-based eluents into pure water, reducing the baseline conductivity. While suppressing the eluent, the ACES 300 also converts the analytes into their more conductive hydronium (acid) form, increasing their sensitivity under conductivity detection. Likewise, when used for cation analysis, the CCES 300 converts highly conductive methanesulfonic acid (MSA) eluents into pure water; simultaneously, the analytes are converted to their more conductive hydroxide form, increasing their sensitivity.

CES 300 Technology

The CES suppressor uses a three-chamber design to minimize dead volume while maximizing suppression capacity and reducing noise.

The eluent chamber is comprised of an ion-exchange capillary membrane that facilitates the efficient exchange of the eluent counter ions for regenerant ions.

The regenerant chambers are divided into ion-exchange and electrode chambers. Regenerant first passes through the ion- exchange chamber, which is filled with a bed of ion exchange resin; the ion exchange capillary membrane is coiled in this bed. The regenerant bed is an ion exchange resin in the opposite form as the eluent. It is this bed of resin that provides the regenerant ions for the capillary membrane eluent chamber.

There are two electrode chambers that are separated from the ion-exchange chamber by a pair of ion exchange membranes. Regenerant, after passing through the ion-exchange chamber, passes through the cathode and anode chambers serially. When current is passed through the electrodes, regenerant ions are generated in the first electrode chamber; these ions are pushed into the ion-exchange chamber via an electric field, maintaining the ion exchange chamber in the regenerant form. After counterions exchange from the eluent ion exchange capillary membrane, they are are removed from the ion exchange chamber via the electric field into the second Electrode chamber. Finally, the counterions are neutralized by the ions generated in the second electrode chamber.


Anion Capillary Electrolytic Suppressor (ACES 300).

CES 300 System Control

The unique design of the CES 300 simplifies software and hardware control options. For most applications, the CES 300 can be set to a single current setting of 10 mA. For applications requiring very high eluent concentrations, the CES 300 should be set to 20 mA. The ICS-5000 includes software and hardware to control the CES 300 suppressor. Chromeleon 6.8 or 7.x is required.

Key Applications Using a CES Suppressor


Separation of 22 anions on an IonPac AS19 Capillary column.


Separation of six common cations using an IonPac® CS12A Capillary column.