Method for the determination of methanol in binary methanol-water mixtures by use of ion-selective electrodes

Abstract

For a given concentration of indicator ion X (X = F^–, Cl^–, Br^–, I^–, OH^–, S^2–, Ag⁺ or H⁺), the systematic change of cell potential, E, with variation in the concentration of methanol provides a graphical method for the rapid determination of methanol in methanol-water mixtures. Readings obtained by direct potentiometry show good reproducibility and stability. In 99.0–99.9%m/m methanol, containing 10^–2M hydrochloric acid, trace amounts of water can be determined accurately owing to a potential “anomaly.”