Purification of silica gel-G Layers

The iron present as an impurity in silica gel-G affords an appreciable distortion of the chromatogram . Hence, it has become almost a necessary step to purify the adsorbent. The iron-free layers may be achieved by providing the pre-coated and air-dried plates a preliminary development with a mixture of methanol and 

The cleaning process usually washes out the CaS04 originally present as binder. Therefore, the silica gel thus obtained by purification may be reused to prepare TLC-plates with other appropriate binders like gypsum, starch etc. 

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