A thin-layer chromatographic method for the determination of “quassin” in cosmetic preparations

Abstract

A method is described by which “quassin” may be determined when used as a denaturant for the alcohol contained in cosmetic preparations. The two bitter principles, neoquassin and quassin are determined together as quassin, after oxidation with a solution of sodium dichromate in glacial acetic acid. Perfume oils are first removed by solvent extraction and the aqueous phase is then evaporated to dryness and the residue oxidised. Further solvent-extraction steps yield a solution of quassin in chloroform which is applied to a thin-layer chromatographic plate. The spots are compared visually with standards prepared from an oxidised “quassin” solution to permit determinations within the range of 5 to 36 p.p.m. in samples.