Design of Miniaturized Ion-Selective Electrodes and Practical Applications

Miniaturized membrane ion-selective electrodes are introduced. The body of electrode is made of a poly(vinyl chloride) tube with an internal porous frit, which is a mechanical support for the membrane. The membrane is created by a one-time or repeated dipping of the electrode tip into the membrane cocktail dissolved in tetrahydrofuran (THF). The thickness of the membrane is controlled by the number of dipping and/or the viscosity of the membrane cocktail, or the amount of THF. The electrodes were characterized in term of repeatability, dynamic response properties, working ranges, and sensitivity. Their analytical performance was compared with literature data for conventional membrane ion- selective electrodes. This electrode design can be a simple alternative to classical/traditional membrane electrodes for various analytical applications.