What elutes first in capillary electrophoresis?
Cations elute first because they have a positive electrophoretic velocity, νe. Anions elute last because their negative electrophoretic velocity partially offsets the electroosmotic flow velocity. Neutrals elute with a velocity equal to the electroosmotic flow.
What is electroosmotic flow in capillary electrophoresis?
Electroosmotic flow is observed when an electric field is applied to a solution in a capillary that has fixed charges on its interior wall. Charge is accumulated on the inner surface of a capillary when a buffer solution is placed inside the capillary.
What does capillary electrophoresis measure?
Capillary electrophoresis is an analytical technique that separates ions based on their electrophoretic mobility with the use of an applied voltage. The electrophoretic mobility is dependent upon the charge of the molecule, the viscosity, and the atom’s radius.
What is capillary zone electrophoresis?
Capillary zone electrophoresis (CZE) is a technique successfully used for the separation of proteins, peptides, and nucleic acids. Other applications where CZE may be useful include analysis of inorganic anions and cations, such as those typically separated by ion chromatography.
What is migration time in capillary electrophoresis?
In electrophoresis, under ideal conditions, nothing is retained, so the analogous term becomes migration time. The migration time ™ is the time it takes a solute to move from the beginning of the capillary to the detector window.
What is capillary chromatography?
Capillary electrochromatography (CEC) is a technique in which the mobile phase is driven through the chromatographic bed by electroosmosis. Capillary electrochromatography is a combination of two analytical techniques, high-performance liquid chromatography and capillary electrophoresis.
Why does electroosmotic flow occur?
Electroosmotic flow occurs because the walls of the capillary tubing carry a charge. The surface of a silica capillary contains large numbers of silanol groups (–SiOH). At a pH level greater than approximately 2 or 3, the silanol groups ionize to form negatively charged silanate ions (–SiO–).
What causes electroosmotic flow?
Electroosmotic flow is caused by the Coulomb force induced by an electric field on net mobile electric charge in a solution.
What is polymer capillary electrophoresis?
Capillary electrophoresis (CE) is a very efficient tool for separating and characterizing synthetic polymers, copolymers, and polyelectrolytes.
What is the difference between capillary electrophoresis and capillary zone electrophoresis?
The key difference between capillary electrophoresis and gel electrophoresis is that gel electrophoresis is performed in a vertical or horizontal plane using a polymer gel of standard pore size whereas capillary electrophoresis is performed in a capillary tube with a polymer liquid or a gel.
What is capillary Isotachophoresis?
Capillary isotachophoresis (cITP) is a technique in which solutes are focussed along the capillary based on their mobility compared to “leading” and “terminating” added solutes which have fast and slow mobilities, respectively.
Which buffer is used in capillary electrophoresis?
Capillary IsoTechoPhoresis (ITP) With this technique two kinds of buffers are used. One buffer with high mobility as a leading buffer and one buffer with very low mobility as a terminating buffer. The mobility of the sample components must be between the leading and terminating.
How does a capillary electrophoresis work?
The analytes separate as they migrate due to their electrophoretic mobility, and are detected near the outlet end of the capillary. The output of the detector is sent to a data output and handling device such as an integrator or computer. The data is then displayed as an electropherogram, which reports detector response as a function of time.
What is surface enhanced Raman scattering for capillary electrophoresis?
“Surface-enhanced Raman scattering: a structure-specific detection method for capillary electrophoresis”. Analytical Chemistry. 72 (21): 5348–55. doi: 10.1021/ac000583v. PMID 11080886. ^ Hjertén S (1985).
What determines the rate of Eof in a capillary buffer?
The rate of EOF is dependent on the field strength and the charge density of the capillary wall. The wall’s charge density is proportional to the pH of the buffer solution.