Procedure
Apply separately 10µLeach of the
Standard solutionand the
Test solutionto a thin-layer chromatographic plate (see
Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture,allow the spots to dry,and develop the plate in a paper-lined chromatographic chamber equilibrated with
Developing solventfor about 15minutes prior to use.Allow the chromatogram to develop until the solvent front has moved about 15cm.Remove the plate,mark the solvent front,and air-dry for 5minutes.Place the plates into a chromatographic chamber containing iodine crystals,and view the spots that develop.
[NOTEFor better detection,overspray the iodine stain with a mixture of alcohol and water (1:1).
]The
RFvalue of the principal spot obtained from the
Test solutioncorresponds to that obtained from the
Standard solution.