Abstract: A dry-operative ion-selective electrode comprising:(a) a dried, internal reference electrode, and(b) in contact with the reference electrode, a hydrophobic ion-selective membrane.The ion-selective electrode described herein requires no preconditioning prior to use in an ion-sensing operation.The reference electrode may comprise either a metal/metal salt reference half-cell or multiple-layer redox couple reference electrode. The hydrophobic membrane includes a binder having dispersed therein a solution of an ion carrier dissolved in a suitable carrier solvent.A preferred embodiment provides for electrodes of the type described wherein the hydrophobic membrane layer is of a predetermined, uniform thickness in regions thereof intended for contact with a sample for analysis. When necessary or desirable, the electrode includes a support. A novel technique for making measurements of ion concentration by reading electrode potential prior to equilibration of the electrode is also described.

Abstract: Halide ion-sensitive devices and methods for their use are described. The devices contain a halide ion-permeable overlayer which is superposed on a layer of silver halide and meets certain criteria of thickness and permeability and/or certain compositional criteria. The methods involve bringing a portion of a solution to be analyzed into contact with the halide ion-permeable overlayer and, within a selected time thereafter, measuring the difference in potential between the portion of solution and the silver halide layer.