Preparation and Storage of Solvent Systems

Every TLC plate has the right to its own fresh soivent system  

An example of the harmful effects of the multiple use of the solvent system is shown in Fig. 51. Four plates, each with two 10-mm lanes, each containing 20 pg metoc-lopramide hydrochloride, were developed successively with the solvent system chloroform + methanol + concentrated ammonia solution (56 + 14 + 1 ml). The continuous downwards shift of the hRf value can be clearly seen, combined with an increasing broadening of the spots of the substance during the chromatography. These effects were caused by the reduction in the amount of base in the remaining solvent. 

10 volumes of water 15 volumes of methanol R 25 volumes of anhydrous acetic acid R 50 volumes of dichloroethane R 

It is recommended in the monographs that the solvent systems should be measmed accurately, as a small excess of water can cause the mixture to be cloudy. Chromatography with this solvent system is described in Section 4.3.1.1 Vertical Development . 

Manufacturer of Type of chamber Dimensions [cm] Bottom Lid Volume of solvent [ml]  

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