A New Glass Cell for Preparative Counter-Current Distribution

Abstract

WE make a distinction between preparative and the usual counter-current distribution. By the latter we mean, of course, the very efficient method of separation based on extraction, devised chiefly by L. C. Craig¹. With this method only a single addition of mixture to the apparatus is possible. This fact, although the amount added can sometimes be fairly large, limits the preparative value of the method. Several columns, working on a continuous basis (repeated or continuous addition of the mixture being possible) have been designed. These columns, however, lack the advantages of counter-current distribution where each cell is completely separated from the others. The principal advantages in this connexion are the easy mathematical interpretation and the possibility of stopping the operation at any time.