About

Capillary electrophoresis is a separation technique in which charged species are separated, based on charge and size, by their different rates of migration in an electric field. The capillary is made of negatively charged fused silica inner wall which forms an electrical double layer with cations in the running buffer. These cations in the electrical double layer move towards the negative cathode and hence the overall direction of flow also known as the electroosmotic movement is towards the cathode.

 

The sample is placed in the running buffer. All analytes will move with the same electroosmotic velocity driven by the running buffer but with different electrophoretic velocity which allows separation. Order of elution would be highest charge and smallest cations would elute first, followed by neutral species and the last to elute would be the highest charge and largest anions.