Hemin-collodion Membrane Electrode for Measurement of Anion Activity in Electrolytic Solutions at Different pH. Part I. Chloride-ion Activities

A thin and uniform film of hemin (hematin hydrochloride), formed by dispersing it in a dilute solution of inert collodion (binder), could be used as a membrane electrode for determination of activity of Cl^— ions in HCL, KCl, NaCI, NH₄Cl, and LiCl in concentration range of 0.0015 to 0.050 M with molarity ratio of 2 and at pH 1.3 to 3.0 in ease of HCI and 4.0 to 7.4 in case of salts to which acetate or phosphate buffers are added.