Page 11 - Illustrated Pocket Dictionary of Chromatography

4 ADJUSTED RETENTION VOLUME, V R ¢

The adjusted retention is the time or volume, t R¢ or V R¢, calculated from the time
of injection, t = 0, to the time or volume peak maximum of the analyte, t R or V R,
less the time or volume it takes for an unretained peak to elute, t M or V M .

adjusted retention volume, V R ¢ The adjusted retention volume
is calculated from the retention volume, V R , and the system void
volume as determined by a nonretained compound, V M :

V R ¢= V R - V M

For GC work this should not be confused with the corrected reten-
tion volume, V R °, which takes into account the compressibility of a
gas.

adsorbent In particular, an adsorbent is a support material used
for adsorption chromatography separations (e.g., graphitized carbon,
silica, alumina, zirconia). However, adsorbent can sometimes be used
in a broader sense to indicate the support material in general.

adsorption The process of a molecule transferring from the
mobile phase and adhering to the surface of the stationary phase. The
adsorption process can be a facile thermodynamic equilibrium, kinet-