An ion sensitive electrode device which consists of one or more ion-pairs distributed in at least one of two or more immiscible phases consisting of an aqueous phase, an organic phase, a polymer phase or a solid electrolyte phase. A reference solution includes an aqueous solution of the ion-pair and...http://www.google.com.au/patents/US5376254?utm_source=gb-gplus-sharePatent US5376254 - Potentiometric electrochemical device for qualitative and quantitative analysis
