Ultrafiltrational concentration of hydrophilic organic substances in the form of azo-derivatives

Ultrafiltrational retaining of azo-derivatives of a wide number of phenols and amines on polysulphonamide membrane has been carried out. Sorption of a substance on the membrane depends on the hydrophobity of its molecule (hydrophylic compounds go through the membrane). The studied compounds have been converted into azo-derivatives by p-nitrophenyldiazonium and then retained on the membrane. The optimal pH ranges made possible to separate some classes of substances. Sorbed compounds can be effectively removed from the membrane so be concentrated.