Graphite base solid state polymeric membrane ion-selective electrodes

摘要

An improved solid-state ion-selective electrode has greater uniformity of asymmetric potential and high sensitivity and selectivity for the cation of interest. The electrode comprises: (1) a porous element (10) comprising graphite; (2) an electrochemical reference (20) in substantially dry form on at least a portion of the element, the reference comprising: (a) an oxidant and (b) a reductant that is the conjugate of the oxidant, the oxidant and reductant being present in about equimolar quantities; and (3) a polymeric membrane (30) comprising an ion-selective ionophore in electrochemical contact with the electrochemical reference. The electrode can be prepared to be selective for one of a number of cations, including lithium and ammonium. Methods for preparing these electrodes are also disclosed.