Limits of detection and selectivity coefficients of liquid membrane electrodes

An equation has been derived theoretically describing the emf of a liquid membrane electrode: E = E(0) - (RT/F) ln[(C + radicalC (2) + A (x))/2]. Experimental data are in good agreement with this equation. The parameter A(x) is related to the limit of detection. When the ion-exchanger dissociates completely in the membrane phase, A(x) is given by 4sigma(2)/b(x). Here sigma represents the concentration of the ion-exchanger in the liquid membrane and b(x) is a quantity related to the ion-selectivity.