When measuring Potassium with an ion-selective electrode by means of a liquid ion-exchange membrane, what antibiotic will be incorporated into the membrane?

Valinomycin

Explanation:

This antibiotic is acquired from the Streptomyces species cells. Valinomycin is selective to potassium and inhibits sodium ions from entering the cell. This antibiotic allows the potassium ions to move down the electrochemical potential gradient of the lipid membranes.