Determination of griseofulvin, carvone and menthone through intermediate oxime formation

Abstract

Two procedures for the determination of griseofulvin, carvone and menthone are proposed, based on the formation and solvent extraction of their corresponding oximes. The first method is based on acid cleavage of the oxime to give the equivalent amount of hydroxylamine, which is oxidised to nitrous acid, the latter being determined through a diazo-coupling reaction. The second method involves semimicro biphasic titrimetry of the oxime with a standard solution of sodium dioctylsulphosuccinate in the presence of a suitable buffer solution. The results obtained with the proposed methods are compared with those of the official titrimetric method. The first method is sensitive to 10 µg ml^–1; the second method is a simple and accurate procedure for the indirect determination of ketonic compounds.