Miniaturized reference electrodes with stainless steel internal reference elements [An article from: Analytica Chimica Acta]

This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Stable reference electrodes have previously been obtained by immersion of a stainless steel internal reference element (SSIRE) in a solution of steady pH, e.g., a stainless steel wire maintained in 2mol/l HCl. Here, we report the miniaturization of this regular size reference half-cell by embedding thermally activated SSIREs in a copolymer matrix of a fixed and constant pH value. The resulting electrode is based on a polymer volume of 1-5@ml, while its contact area at the polymer/analyte solution interface is 0.4mm^2. Photopolymerized acrylic type hydrogel is used as the copolymer which contains a quaternary ammonium salt as the supporting electrolyte. These miniaturized reference electrodes show potential stability over the pH range of 1-13, maintain a constant potential value over the time, and are suitable for potentiometric and voltammetric measurements in both aqueous and organic media. Furthermore, they do not exhibit leakage problems. Hence, they do not contaminate the analytical sample, even when the reference electrodes (REs) are used in very small volumes and over extended period.