Page 93 - Illustrated Pocket Dictionary of Chromatography

G

gas-liquid chromatography (GLC) This technique utilizes a
gas as the mobile phase and a solid support material that is coated
with a liquid stationary phase. The stationary phase must have a high
boiling point (to prevent it from volatilizing off the support and out of
the column). Liquid stationary phases include such materials as poly-
siloxanes and polyethyleneglycols. These are derivatized with various
functional groups such as methyl, phenyl, and cyano, to produce
phases of varying polarity.

gas-solid chromatography (GSC) This technique utilizes a gas
mobile phase and an unmodified adsorbent support such as silica or
alumina for generating separation.

Gaussian curve The Gaussian curve is generated from the Gauss
function:

2 2
-
F x,s = [1 s÷2 p]e -( xx i ) 2 s

where x is the center of the distribution (mean) and s is the width
(deviation) of the distribution. This equation is used to describe chro-
matographic theory from which analytical parameters such as reten-
tion time, area, and symmetry are calculated.

Illustrated Pocket Dictionary of Chromatography, by Paul C. Sadek.
ISBN 0-471-20021-2 Copyright © 2004 John Wiley & Sons, Inc.
89