In thin layer chromatography (TLC) [1,2] a small amount of
an analyte or mixture of analytes is spotted onto a TLC plate,
which consists of a backing material that supports a
chromatographic stationary phase. The most common stationary
phase is uncoated, or normal phase, silica gel that is held
on the plate by a binder. After spotting, the end of the plate is
placed in a solvent reservoir and the solvent, which is the
chromatographic mobile phase, moves up the plate by capillary
action. The analytes partition themselves between the
stationary and mobile phases and therefore move up the plate
at some rate, which is generally less than the rate of the mobile
phase. The distance the analyte travels divided by the distance
the mobile phase travels is known as the RF.
For TLC to be successful, a visualizing method must be
found to (ideally) allow both the locations and the identities of
the separated analytes to be determined. For example,
ultraviolet light is used to visualize analytes that quench an
inorganic fluorescent agent that is commonly added to the