Selection of the Solvent
The solvent is selected according to elution strength. With the help of a quick test you can test different solvents and find the suitable one.
It is common to use a glass capillary as a dot or short line. Too wide substance zones during application lead to poor separation, as the zones become even wider during separation. After application, the solvent is allowed to evaporate, which can be accelerated by using a dryer.
A common method is to use a development chamber. The eluent is poured into the bottom of the chamber. The saturation of the chamber with the solvent vapour is necessary for a reproducible running distance. The TLC plate with the sample is then positioned in the chamber. The separation is complete when the eluent has risen to the upper end of the TLC plate. Now the TLC plate can be removed and dried accordingly.
The evaluation depends on the aim of the chromatographic analysis. For qualitative determinations it is easiest to run comparison substances. Quantitative evaluations are possible via corresponding calibration measurements. The area of the substance spots is used or a photometric evaluation is carried out on the layer. However, the latter requires more equipment.