Fabrication and evaluation of an electrodialytic carbonate eluent generator for ion chromatography

• A high pressure electrodialytic K2CO3 eluent generator is described.
• A KHCO3 pH modifier is fabricated to online modify the pH of eluent.
• K2CO3 eluent generator produces the eluent linearly with the current.

An electrodialytic potassium carbonate eluent generator and its associated potassium bicarbonate eluent generator have been fabricated for ion chromatography (IC). The device can withstand high backpressure up to ∼32 MPa and no observable leakage under such pressure is found during 2 h. In the range of 0–13.7 mM, potassium carbonate concentration can be generated linearly with the applied current with a slope that is essentially Faradaic. At least 10 mM potassium carbonate can be online changed into 10 mM potassium bicarbonate via a potassium bicarbonate eluent generator, which offers an easy way to manipulate the separation selectivity. When coupled with IC system, the device demonstrated good reproducibility indicated by less than 0.52% of the relative standard deviation of the retention times.

An electrodialytic potassium carbonate generator for ion chromatography has been fabricated and evaluated. It generates eluent at near-Faradaic efficiency and bears backpressure up to ∼32 MPa.Figure optionsDownload as PowerPoint slide