Ion Selective Electrode

The conversion of the activity of a specific ion into an electrical potential through a sensor membrane electrode is called Ion Selective Electrode.

The electrode that observes the activity of ions in an aqueous solution by measuring an electrical potential is known as an ion-selective electrode. This is also called a specific ion electrode. It works to sense specific ions.

Principle of ion-selective electrode:

An ideal ion-selective electrode consists of a thin membrane across which only the intended ion can be transported. The transport of ions from a high concentration to a low concentration through selective binding with some sites within the membrane creates a potential difference.

 

Advantages of Selective Ion Electrode:

• ·        It is very cheap and easy to operate.
• ·        They are resistant to solvent and chemical attacks.
• ·        It has a wide range of concentration measurements.
• ·        It is used in biological and medical applications as well.
• ·        It is used for both colored and turbid solutions.
• ·        It can monitor the change of activity with time.
• ·        It can determine both negatively and positively charged ions.

Types of Ion Selective Electrode:

The electrode is classified concerning its membrane material. There are five types which are given below:

• 1.     Glass Membrane Electrode
• 2.     Crystalline or Solid State Electrode
• 3.     Gas Sensing Electrode
• 4.     Liquid Membrane Electrode
• 5.     Enzyme Electrode or Biochemical electrode