POTENTIOMETRIC TEST STRIP

A potentiometric test strip has been developed. It consists of an indi cator electrode and a reference electrode. Both electrodes are prepare d on filter paper as a microfibre matrix, encapsulated by the use of h eat-sealing film and separated by an insulating plastic film or held a t a distance during measurement. The reference electrode is a redox el ectrode. For the preparation of the ion-selective electrode a standard ion-selective PVC-matrix membrane cocktail is deposited in the microf ibre matrix. Potassium- and sodium-sensitive test strips have been pre pared and characterized. The electrochemical response of the potentiom etric test strips is close to that of macro ion-sensitive electrodes u sing the same ion-selective membrane material. It should be possible t o produce the test strips by mass-production technologies. So in futur e they may offer a new possibility for a more precise low-cost on-site determination of ions.