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PubMed · 15987098

Monolithic capillary-based ion-selective electrodes.

Tamás Vigassy·Christian G Huber·Reiner Wintringer·Ernö Pretsch
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Abstract

Poly(styrene-co-divinylbenzene)-based monolithic capillaries of an inner diameter of 200 mum and a length of 2-5 mm have been used to construct Ca2+-, Ag+-, and Na+-selective electrodes. The membranes consist of a solution of ionophore and ion exchanger in bis(2-ethylhexyl) sebacate or 2-nitrophenyl octyl ether, which are used as plasticizers in conventional PVC-based membranes. With capillaries of low porosity, the potentiometric responses down to 10(-8)-10(-9) M solutions do not depend on the composition of the internal solution, which indicates a strong suppression of transmembrane ion fluxes. Thus, no tedious optimization of the inner solution is required with monolith ISEs. The lower detection limits of Ag+- and Ca2+-ISEs are comparable to the best ones obtained earlier with optimized inner solutions. Additionally, a monolithic Na+-selective ISE has been obtained exhibiting a lower detection limit of 3 x 10(-8) M Na+. With monolithic capillaries of higher porosity and fused-silica GC capillaries, the transmembrane flux effects are noticeable but still significantly smaller than with conventional PVC membranes.

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CalciumElectrochemistryIon-Selective ElectrodesPolystyrenesSilverSodiumJournal ArticleResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov't

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Tamás Vigassy, Christian G Huber, Reiner Wintringer, Ernö Pretsch. 2005-07-01. Monolithic capillary-based ion-selective electrodes.. https://doi.org/10.1021/ac050424h

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