PH electrode protective solution is a liquid used to protect pH electrodes, usually a 3mol/L potassium chloride solution. Its main function is to extend the service life of the electrode and ensure the accuracy of measurement.

The method of preparing pH electrode protective solution includes the following steps:

Firstly, calculate the required mass of potassium chloride (KCl), typically 223.5 grams; Then accurately weigh KCl using an analytical balance and dissolve it in distilled water in a beaker; Next, transfer the solution to a 1000ml volumetric flask and wash the beaker and glass rod with distilled water to ensure that all solutes are transferred to the volumetric flask; Finally, obtain a uniform solution by adjusting the volume and shaking well;

Electrode function:

Preventing electrode drying: PH electrodes exposed to air for a long time are prone to drying due to moisture evaporation, leading to a decrease in electrode performance. The protective solution can effectively maintain the moist state of the electrode and extend its service life.

Avoid electrode contamination: During the measurement process, the pH electrode may come into contact with various chemical substances, which may remain on the electrode and affect the accuracy of subsequent measurements. The protective liquid can form a protective film to prevent the electrode from being corroded by pollutants.

Slowing down electrode aging: The pH electrode will gradually age over time, manifested as slower response speed and decreased accuracy. Some components in the protective solution can slow down the aging rate of the electrode and maintain its measurement accuracy.

Providing a stable ionic environment: Protective solutions, especially saturated potassium chloride solutions, can provide a stable ionic environment that helps maintain the electrochemical performance of the electrode and reduce the impact of external interference on measurement results.