Potassium ion selective electrode (ISE) operates based on the principle of selective ion permeability through a membrane. The membrane is typically made of crystalline materials or polymers with a specific affinity for potassium ions. When immersed in a sample solution, the electrode selectively allows potassium ions to pass through, generating a potential difference proportional to the logarithm of the potassium ion activity.
Tips: How is the selectivity of a potassium ion selective electrode achieved?
The selectivity of a potassium ion selective electrode (KISE) is achieved through the use of a membrane that selectively permits the passage of potassium ions while excluding interference from other ions. The membrane typically contains a selective ionophore specific to potassium ions, which facilitates their selective transport across the membrane. The ionophore interacts preferentially with potassium ions due to its specific molecular structure, creating a membrane that is permeable to potassium but resistant to other ions. This selectivity is crucial for accurate and reliable potassium ion measurements in analytical applications. Additionally, the electrode may incorporate a reference electrode to maintain a stable potential, enhancing the overall performance of the KISE. The careful design of the membrane and the use of appropriate materials contribute to the selectivity and sensitivity of the potassium ion selective electrode.