Determination of Diammonium Glycyrrhizinate and Its Antioxidant Activity Using a Novel Chemiluminescence System

Abstract

A novel chemiluminescence (CL) system was established for the determination of diammonium glycyrrhizinate (DG) in pharmaceutical preparations and its ability of scavenging hydroxyl radical. It was shown that a strong CL signal was observed when Eosin Y mixed with Fenton reagent. The CL intensity was decreased significantly when DG was added to the reaction system and partially scavenged the hydroxyl radicals in the solution. The extent of decrease in the CL intensity had a good stoichiometrical relationship with DG concentration. Based on this, we developed a new method for the determination of DG using a flow injection chemiluminescence (FI-CL) technique. Under the optimal conditions, the linear range of DG concentration was 6.0 × 10−8–5.0 × 10−6 mol/L (R = 0.9982) with a detection limit of 8.0 × 10−9 mol/L (SN = 3), and the RSD was 3.8% for 2.0 × 10−7 mol/L DG (n = 11). This method was successfully used in the determination of DG in tablets and the evaluation of hydroxyl radical scavenging capacity of DG. The possible reaction mechanism of the CL system is discussed.