Page 30 - Illustrated Pocket Dictionary of Chromatography

CAPILLARY GEL ELECTROPHORESIS (CGE) 25

of columns that have uncoated fused silica supports. When the
support is coated, the class of columns is called wall-coated OT
(WCOT). Porous open OT (PLOT) columns have a porous support
deposited on top of the fused silica material. Finally, support-coated
OT (SCOT) columns pack very small support particles in the capillary
tube and then the entire packing material is coated with liquid phase.
They are rarely used today. These columns are manufactured from
fused silica that is clad with aluminum, polyimide, or stainless
steel. (2) Various types of capillary columns are used in the field of
capillary electrophoretic techniques. These are similar, if not identi-
cal, to the type used in GC. (3) Capillary columns for LC work ranges
from 0.02 to 0.004in. in inner diameter and are made from stainless
steel.

Left: A 10-m GC capillary column. Right: A 60-m GC capillary column. Note the
thinness of the column (lower right column shows end of column) and the cage
that the columns are wound around for support. The cage is also used to keep the
column from touching the walls of the oven. The metal tag affixed to the left-hand
side of the 60-m column is the identity tag for the column (including phase, ID,
length, serial number, etc).

capillary electrochromatography (CEC) A technique that
uses a packed capillary column and electroosmotic flow to generate
a separation.

capillary zone electrophoresis (CZE) A capillary elec-
trophoresis technique that generates a separation based on a poten-
tial developed across an open tube fused-silica capillary column.

capillary gel electrophoresis (CGE) A technique that mimics
classic slab gel electrophoresis but places the gel within a capillary
column.