| abstract |
A device for determining ionic activity is composed of plural pairs of ion-selective solid electrodes (26) each pair having two electrodes (one electrode on each of two sides) and each pair having a different type of ion-selective layer (26a, 26b, 26c); two liquid distribution porous members (32), each member being disposed overall the electrodes (26) or each said side of the plural pairs; and a porous capillary bridge (38) disposed on or between the liquid distribution porous members. The bridge (38) can be in liquid contact with all the electrodes (26) through the liquid distribution porous members (32) and achieve electrical conduction between two electrodes in each pair after spotting a test solution and a reference solution. The device preferably further comprises a support from (28) and a cover (35) having two apertures (36) for liquid spotting. n The device can simultaneously determine ionic activities of a plurality of different ions in a test solution, such as whole blood, plasma, serum or urine, by spotting a test solution and a reference solution each in one operation and measuring the eletrical potential difference of each pair. |