ABSTRACT
Development .................................................................................... 125 7.2.4 Automatic Chambers ....................................................................... 125
7.3 Sample Application...................................................................................... 129 7.3.1 Sample Application in Analytical TLC........................................... 129 7.3.2 Sample Application in Preparative Layer Chromatography............ 130
7.4 Chromatogram Development ....................................................................... 131 7.4.1 Mobile Phases Applied in TLC....................................................... 131
7.4.1.1 Solvent Properties and Classification ............................... 137 7.4.1.2 Optimization of the Mobile Phase Composition .............. 143
7.4.2 Classification of the Modes of Chromatogram Development ......... 147 7.4.2.1 Linear Development ......................................................... 147 7.4.2.2 Radial Development ......................................................... 162
7.5 Combinations of Different Modes of Chromatogram Development........... 164 7.6 Conclusions.................................................................................................. 168 References ............................................................................................................. 169
Stages of planar chromatography procedure such as sample application, chromatogram development, registration of chromatogram, and its evaluation cannot be presently performed in one run using commercially available device. It means that
planar chromatography analysis is not completely automated at contemporary laboratory practice. Opposite situation is in other liquid chromatography techniques of which the procedures are completely automated and proceed in one run. The present status of thin layer chromatography (TLC) will be probably continued in the near future too and however, there are no signals at present which could indicate that this situation will be changed in a distant future. Chromatographers have to separately optimize each of the mentioned stages using more or less sophisticated devices. There are various equipments for hand-semi-or full-automatic operations at mentioned stages of planar chromatography procedures. At each stage of TLC procedure chromatographer should demonstrate basic skill, which substantially helps to accomplish TLC experiments correctly, to obtain reliable, repeatable, and reproducible results. He=she can meet many pitfalls during work with TLC mode. There are some fundamental books which help to overcome these problems [1-4]. In this chapter we give some information that can draw the reader’s attention to the procedures and equipments mentioned earlier, which are more often applied and proven in contemporary planar chromatography practice. We hope that the reader will gain this information to avoid some problems concerned with performing TLC experiments when reading this chapter.
