The Spectrofluorometric Determination of Anthraquinone with Hydroxylamine in the Dimethyl Sulfoxide Medium Containing Sodium Methoxide and Methanol

Abstract

Abstract Anthraquinone reacts with hydroxylamine in the dimethyl sulfoxide (DMSO) medium containing sodium methoxide and methanol. Since the reaction product is fluorescent in the medium, this reaction can be used for the fluorometric determination of anthraquinone. A DMSO solution of a sample was mixed with a DMSO solution of hydroxylamine hydrochloride and a methanolic solution of sodium methoxide. The mixture was then allowed to stand for 20 min at 60 °C in a volumetric flask with a tightly fitting stopper. After cooling and dilution to the mark with DMSO, the fluorescence intensity of the solution was measured at 597 nm, with excitation at 494 nm. The intensity was stable for at least 2 h in the tightly stoppered flask. The determination limit of anthraquinone was 100 ng. By the application of this spectrofluorimetry, anthraquinone in 9,10-phenanthrenequinone could be successfully determined over the content range from 0.2 to 4%.