DETERMINATION OF IRON IN CHINESE HERBAL MEDICINE BASED ON THE FLUORESCENCE QUENCHING OF RHODAMINE 6G

Abstract

A fluorescence quenching method was developed for determination of Fe³⁺ with rhodamine 6G as fluorescent reagent. Fe³⁺ reacting with KI in diluted sulfuric acid produced I₃^- anion which reacted subsequently with rhodamine 6G to form a non-fluorescence compound. As a result, the compound quenched the fluorescence intensity of the system. The fluorescence intensity decreased linearly with the Fe³⁺ concentration in the range from 20 to 200 μg/L. The detection limit was 8.3 μg/L. This method has been applied to determine the iron in Chinese herbal medicine with satisfactory results.
KEY WORDS: Rhodamine 6G, Fluorescence quenching, Iron

Bull. Chem. Soc. Ethiop. 2009, 23(1), 113-116.