Page 170 - Illustrated Pocket Dictionary of Chromatography

RUGGEDNESS 171

where a is a constant used to adjust P to 100 for the most polar phase,
oxydipropionitrile, u is the nonpolar phase, and p is the polar phase.

rotation planar chromatography (RPC) A TLC technique
uses centrifugal force to accelerate the solvent flow from the center
of the plate. See radial thin-layer chromatography.
ruggedness The ruggedness of a method is a measure of how sus-
ceptible a result is to changing one operating parameter in the system.
Ruggedness is determined through the purposeful and controlled
modification of operating variables over the expected range of vari-
ability. For example, if an HPLC separation is optimized with a
60/40/0.1 v/v/v methanol-water-trifluoroacetic acid mobile phase, then
the effect of a change on the methanol-to-water ratio of ±1% and the
TFA ratio ±0.02% will be determined. If these changes have no effect
on the analytical result (not on the retention times) in terms of all
the acceptability parameters being met, then the method is rugged
with respect to these operating variables.