Analytical Sciences

Abstract − Analytical Sciences, 18(9), 977 (2002).

A New Spectrofluorometric Method for the Determination of Ascorbic Acid Based on Its Activating Effect on a Hemoglobin-Catalyzed Reaction
Ruiyong WANG, Zhihong LIU, Ruxiu CAI,  and Xiaoyan LI
Department of Chemistry, Wuhan University, Wuhan 430072, P. R. China
A spectrofluorometric method for the determination of ascorbic acid (AA) based on its activation on the hemoglobin-catalyzed reaction was proposed. The fluorescence intensity of the product was measured under the optimal experimental conditions, i.e. 4.0 x 10-6 M H2O2, 6.0 x 10-5 M p-cresol, 1.2 M NH3-NH4Cl (pH 10.4) and 2.0 x 10-7 M hemoglobin. The order of additions of the reagents was also studied. The activation of AA was found to be associated with a high ammonia concentration. The linear range of the method was 9.0 x 10-10 - 3.6 x 10-8 M of AA. The detection limit was calculated to be 3.0 x 10-10 M. The relative standard deviation of this method is 1.6% at 7.0 x 10-9 M for 11 determinations.