On-Line Gas-Free Electrodialytic Eluent Generator for Capillary Ion Chromatography
- 7 December 2007
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 80 (1), 40-47
- https://doi.org/10.1021/ac701889x
Abstract
Both low- and high-pressure, gas-free, capillary-scale electrodialytic generators for eluents in ion chromatography are described. While the low-pressure devices rely on planar or tubular membranes, the high-pressure devices rely on ion-exchange beads used both as one-way ionic gates and as ball-on-seat valves to provide sealing. The high-pressure device is easily implemented in the form of a commercial cross fitting and can withstand at least 1400 psi. By design these devices do not produce gas in the eluent channel; hence, it is not necessary to remove gas afterward. With appropriate electrolytes and electrode polarities, such devices can produce either acid or base or salt. In regard to ionic transport, the behavior of these devices fully corresponds to that of a semiconductor diode. To our knowledge, this is the first time such complete equivalence of ion transport through ion-exchange media and with the more familiar example of electron transport through a semiconductor diode under both forward- and reverse-biased conditions have been demonstrated. Reverse bias can be applied to minimize/prevent Donnan-forbidden leakage or ion exchange. Even with 4 M KOH in the electrode compartments and 4 μL/min water flowing through the eluent channel, with a reverse bias of −12 V, the leakage KOH concentration is <30 μM, whereas the KOH concentration with zero voltage applied, hereinafter termed open circuit penetration (OCP), is 1600 μM. It is suggested that this OCP occurs not as much through Donnan-forbidden leakage but via ion exchange. Chromatograms and reproducibility data are presented for both isocratic and gradient chromatography, using ion-exchange, latex-modified, open tubular and packed monolithic columns.Keywords
This publication has 8 references indexed in Scilit:
- Open Tubular Anion Exchange Chromatography. Controlled Layered Architecture of Stationary Phase by Successive Condensation PolymerizationAnalytical Chemistry, 2007
- Preparation and Application of Methacrylate-Based Cation-Exchange Monolithic Columns for Capillary Ion ChromatographyAnalytical Chemistry, 2004
- Compact, field-portable capillary ion chromatographJournal of Chromatography A, 1998
- Capillary Ion Chromatography with On-Line High-Pressure Electrodialytic NaOH Eluent Production and Gradient GenerationAnalytical Chemistry, 1997
- Two-dimensional conductometric detection in ion chromatography: sequential suppressed and single column detectionAnalytical Chemistry, 1993
- Electrodialytic eluent generation and suppression : Ultralow bacground conductance suppressed anion chromatographyJournal of Chromatography A, 1991
- Electrodialytic production of gas-free sodium hydroxide based on Donnan breakdownJournal of Membrane Science, 1991
- Electrodialytic eluent production and gradient generation in ion chromatographyAnalytical Chemistry, 1991