Electrolytes are commonly measured by what method?

• A. Ion-specific electrode
• B. Refractometry
• C. Adsorption
• D. Enzymatic digestion

Answer: (A)

Measuring electrolytes hinges on detecting the activity of specific ions in a solution. An ion-specific electrode is designed with a membrane that selectively responds to a particular ion (such as sodium, potassium, or chloride). When the electrode is immersed in a sample, the selective membrane generates a potential that correlates to the ion’s activity, meaning the sensed concentration effectively. This electrical signal is interpreted using the Nernst equation, giving a direct, rapid, and specific readout of the electrolyte level. This approach is standard in clinical labs because it provides fast and accurate measurements for individual ions.

Refractometry, by contrast, measures how light bends through a solution to estimate total solute concentration, not the identity or amount of specific ions. Adsorption describes how substances adhere to surfaces, not how you quantify dissolved ions. Enzymatic digestion is used to break down biological macromolecules, not to measure electrolyte ions.