Response of ion-selective sodium and potassium electrodes in the Beckman Astra 4 and Astra 8 analyzers.

We tested the response of ion-selective sodium and potassium electrodes that are a part of the new multi-channel chemical analyzers, Astra 8 and Astra 4 (Beckman). For this we used plain and albumin-containing aqueous solutions of known Na+ and K+ concentrations, varied inversely so we could assess how the concentration of each electrolyte would affect the response of the other electrode. The stability of the electrodes with time was good and the electrodes are indeed selective for Na+ and K+.