Page 69 - Academic Press Encyclopedia of Physical Science and Technology 3rd Analytical Chemistry

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Encyclopedia of Physical Science and Technology EN002E-79 May 17, 2001 20:28

Capillary Zone Electrophoresis

Tim Wehr
LC Resources, Inc.

I. Principles of Capillary Electrophoresis
II. Band Broadening in Capillary Electrophoresis
III. Capillary Electrophoresis Instrumentation
IV. Capillary Electrophoresis Separation Modes
V. Capillary Zone Electrophoresis
VI. Capillary Isoelectric Focusing
VII. Capillary Sieving Techniques
VIII. Isotachophoresis
IX. Micellar Electrokinetic Chromatography
X. Capillary Electrokinetic Chromatography

GLOSSARY an electric field is applied to a capillary carrying fixed
charges on the inner surface.
Anolyte Acidic solution (usually dilute phosphoric acid) Isoelectric point The pH at which an amphoteric species
used to terminate the anodic end of the pH gradient in (such as a polypeptide) has zero net charge and does
isoelectric focusing. not migrate in an electric field.
Carrier ampholytes Synthetic amphoteric compounds Jouleheat Theheatingofaconductivemediumascurrent
containing acidic and basic functions which migrate flows through it.
under the influence of an electric field to form a stable Plate height In chromatography and electrophoresis, the
pH gradient in isoelectric focusing. The composition measure of the amount of dispersion or spreading of a
of the carrier ampholyte mixture defines the extent and zone or peak during the separation process.
shape of the pH gradient.
Catholyte Basic solution (usually dilute sodium hydrox-
ide) used to terminate the cathodic end of the pH gra- CAPILLARY ELECTROPHORESIS (CE) is a rela-
dient in isoelectric focusing. tively new separation technology which combines aspects
Chiral selector Additives used in capillary electrophore- of both gel electrophoresis and high-performance liquid
sis and electrokinetic chromatography which complex chromatography (HPLC). Like gel electrophoresis, the
differentially with enantiomers such that the complexes separation depends upon differential migration in an
migrate at different rates. electrical field. Since its first description in the late 1960s,
Electroosmotic flow Bulk flow of the electrolyte when capillary electrophoretic techniques analogous to most

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