Improved amine spray reagent for the detection of sugars

Abstract

In the course of our investigations on naturally occurring flavonoid glycosides, the sugars obtained after acid hydrolysis were mainly analysed by gas-liquid chromatography and/or paper chromatography, using p-anisidine phosphate as the spray reagent. Often only very small amounts of the isolated compounds are available, in which case the flavonoid aglycone, possible degradation products and sugars resulting from the acid hydrolysis are analysed by paper chromatography on the same sheet. Flavonoids are detected by, e.g., measuring their UV fluorescence, which can be intensified by spraying with diphenylboric acid-ethanolamine ester (flavone reagent), and the sugars can subsequently be detected by overspraying with p-anisidine phosphate followed by heating at 100-120°.