Page 43 - Illustrated Pocket Dictionary of Chromatography
P. 43
38 COLUMN SWITCHING
Column switching is an elaborate form of sample preparation in which a sample is
loaded onto column 1 with a mobile phase generated by pump 1. Once the
unwanted contaminants, etc., are flushed through column 1 to waste, the flow path
is switched so that pump 2 now elutes sample on column 1 in the opposite direc-
tion and onto column 2, where further separation occurs. Often columns 1 and
2 and mobile phases from pumps 1 and 2 are very different in order to trap the
analytes of interest on column 1 and then separate them on column 2 with a very
different mobile phase.
