Shorter response times and improved selectivity for potentiometric electrodes

Abstract

The response times of potentiometric electrodes of the coated-wire variety are shortened by the addition of non-selective charge carriers to the ion-selective membrane. As a charge carrier, ferrocene was effective in decreasing the response time by a factor of 2–3, e.g. from 19 to 6 s. The optimum amount of ferrocene in the polymer film was 1.5% (w/w). As an unexpected benefit, the selectivity of the electrodes containing ferrocene improved by up to two orders of magnitude.