Introduction of ion selective electrode

Ion selective electrode is also called ion electrode. An electrochemical sensor uses membrane potential to determine the activity or concentration of ions in solution. 1906 glass electrode for measuring PH value of solution was first invented by R. cremer and then made by F.Harber. By the end of 1960s, there were more than 20 kinds of ion-selective electrodes. Ion selective electrode has the ability to convert the activity of specific ions in solution into a certain potential, and its potential is linearly related to the logarithm of the activity of given ions in solution. Ion selective electrode is a kind of membrane electrode, and its core component is the sensing membrane at the tip of the electrode. According to the structure, it can be divided into solid membrane electrode, liquid membrane electrode and diaphragm electrode. Ion-selective electrode method is a branch of potentiometric analysis, which is generally used in direct potentiometric method and potentiometric titration. The characteristics of this method are as follows: ① Determine the activity of specific ions in solution, not the total concentration; (2) Simple and rapid use, wide application range, especially suitable for the determination of alkali metals, nitrate ions, etc. (3) It is not affected by the color and turbidity of the test solution, and is especially suitable for continuous automatic monitoring and on-site analysis of water quality. At present, the ion-selective electrode method for the determination of PH and fluoride ions has become a standard method, and the ion-selective electrode method has been adopted in many projects of 10 in the water quality automatic continuous monitoring system.