Question

What is the principle of separation by CZE?

Short answer

The capillary zone electrophoresis is widely used due to its simplicity and easy method. The nature solution also remains unaffected by the separation.

Step-by-step solution

Step 1. Given information

State the principle of separation by CZE.

Step 2. Capillary zone electrophoresis 

The capillary zone electrophoresis (CZE) is a type of electrophoresis in which separation of buffer solution takes place because of electroosmotic flow. The buffer solution remains constant throughout the separation process. The rate of electroosmotic flow controls the rate of migrating particles. The ionic compounds are easily separated by this method. The separation solution depends on the physical characteristics of the compound such as hydrodynamic radius, charge, and ionic force of ions.

Step 3. Principle of capillary zone electrophoresis

The instrument of capillary zone electrophoresis consists of a capillary tube with fused silica and two electrodes anode and cathode. The detection of the sample is done by introducing the sample solution on one end of the capillary tube and detected on the other end. A high voltage is applied across the electrodes.

For separation of cations, the capillary tube is untreated and movement of ions and electroosmotic flow become towards the cathode. For separation of anions, the capillary tube is treated to reverse the movement of electrosoomotic flow by an alkyl ammonium salt. The ions attached with ammonium salt creates a positively silica surface. To oppose the positive silica surface a negative mobile solution layer is created. This negative mobile solution layer is attracted by the anode and reverses the electroosmotic flow.