Traditional sample preparation methods are still widely
used before TLC analysis. For example, in the analysis for
degradation products of endosulfate, the toxic metabolite of
endosulfan, microbial culture samples were extracted with
ethyl acetate, residual water was removed by passage through
a 6 cm magnesium sulfate column in a Pasteur pipet, organic
solvent was evaporated, and the residue was reconstituted in
acetone for application to a TLC plate (4). As an example of
the use of traditional extraction and purification methodology,
samples of Juniperus procera tree were ground, dried, and
Soxhlet-extracted with hexane–dichloromethane (1 + 2), and
the extracts were cleaned up ona1m 2.5 cm silica gel column
by elution with hexane followed by dichloromethane–hexane
(1 + 4). Silica gel TLC of the extracts identified
10 major alcohol, phenol, and acid compounds that were
potential antitermite agents (5).