Scientific article

Flow Chronopotentiometry with Ion-Selective Membranes for Cation, Anion, and Polyion Detection

Published inAnalytical Chemistry, vol. 88, no. 7, p. 3945-3952
Publication date2016

We report here on the development of a chronopotentiometric readout for ionselective electrodes that allows one to record transition times in continuous flow conditions without the necessity to stop the flow. A sample plug of 150 μL is injected into the carrier solution (0.5 mM NaCl) and subsequently transported to the detection cell (∼20 μL) at moderate flow rates (∼0.5 mL min−1), where a short current pulse (5s) is applied between the ionophore-based working electrode and a biocompatible and nonpolarizable Donnan exclusion anion-exchanger membrane reference/ counter electrode. Flow conditions bear an influence on the thickness of the aqueous diffusion layer and result in a shift of the chronopotentiometric transition time with respect to stopped flow. Two models based on rotating disk electrodes and flow chronopotentiometry at metal-based electrodes were used to corroborate the data. The method was successfully applied to the determination of calcium, chloride, alkalinity, acidity, and protamine with a range of ion-selective membranes. Because of the limiting exposure time of ca. 20 s of the membranes with the sample, this approach is demonstrated to be useful for the detection of protamine in the therapeutic range of undiluted human blood.

Research group
Citation (ISO format)
GHAHRAMAN AFSHAR, Majid, CRESPO PARAVANO, Gaston Adrian, BAKKER, Eric. Flow Chronopotentiometry with Ion-Selective Membranes for Cation, Anion, and Polyion Detection. In: Analytical Chemistry, 2016, vol. 88, n° 7, p. 3945–3952. doi: 10.1021/acs.analchem.6b00141
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Article (Published version)
ISSN of the journal0003-2700

Technical informations

Creation10/19/2017 4:45:00 PM
First validation10/19/2017 4:45:00 PM
Update time03/15/2023 2:10:12 AM
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