Nanovolume Gas-Free Hydroxide Eluent Generator for Open Tubular Ion Chromatography.

Author(s) Chouhan, B.; Shelor, C.Phillip; Huang, W.; Chen, Y.; Dasgupta, P.K.
Journal Anal Chem
Date Published 2020 Mar 06

A gas-free KOH eluent generator (EG) with 210 nL internal volume is described. It utilizes a two-membrane configuration where there is a single CEM layer on one side and a single BPM layer on the other side for use in open tubular ion chromatography systems with typical back pressures <50 psi. At a flow rate of ~190 nL/min, the 10-90% gradient rise time is 3.5 min. The device shows good linearity between applied current and concentration of KOH generated, which is stable over extended periods. The overall system reproducibility (that includes contribution, as judged by the relative standard deviation (RSD) of the retention times of individual separated ions in repeat meas-urements (n=6) ranged from ˂0.5 % for isocratic to ˂1.2 % for gradient elution schemes. Perceptible current flow and KOH production in the BPM-based EG begins at subelectrolytic applied voltages, prompting us to look more closely at exact field strength necessary for field-enhanced dissociation of water. An increase in the specific conductance of pure water is noticeable by a field strength of 100,000 V/m.

DOI 10.1021/acs.analchem.0c00505
ISSN 1520-6882
Citation Anal Chem. 2020.

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