Zones and Extraction

Percolation is the least drastic and probably most stiitable procedure for dissolving out substances from the adsorbent. The scraped-off adsorbent is placed in a conveniently sized glass tube, e. g., an Allihn tube or a tube with a sintered glass filter (G 3) and tap. An eluent is then 

In any case it is thus advisable to remove the solvent from the substances, to redissolve the latter and, after filtration through a very fine filter, to crystallise from an appropriate solvent. 

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