Capillary Electrophoresis System Agilent 7100 Principle

Capillary electrophoresis is a qualitative and quantitative analytical method of the separated components by performing electrophoresis in a capillary tube with an inner diameter of 100 μm or less.

[Procedure]

• Fill the capillary tube with the migration solution.
• Inject the sample into the capillary tube.
• Immerse both ends of the capillary tube into the migration solution and apply a high electric field.
• Each component is separated while migrating by electrophoresis.
• Each component is recorded as a peak in the order of reaching the detector.

Normally, the inner wall of a capillary tube is negatively charged by the silanol group, which causes cations in the liquid to collect on the wall. When an electric field is applied, these cations migrate to the negative electrode with the solvent in tow. This flow is called electroosmotic flow and acts like a liquid chromatographic (LC) pump. The sample undergoes electrophoresis while flowing with the electroosmotic flow, and each component is separated according to differences in charge and Stokes radius.