Determination of Puerarin in Pharmaceutical Injection by Flow Injection Analysis with Acidic Potassium Permanganate–Glyoxal Chemiluminescence Detection

Abstract

A simple flow injection chemiluminescence method with synergistic enhancement has been investigated for the rapid and sensitive determination of puerarin. The method is based on the enhancing effect of puerarin on the chemiluminescence emission generated by the oxidation of glyoxal with potassium permanganate in a sulfuric acid medium. The optimization of chemical variables influencing the chemiluminescence response of the method has been carried out by applying experimental design, using the proposed flow−injection manifold. Under the optimal conditions, the enhanced chemiluminescence intensity was linear with the concentration of puerarin over the range from 10.0 ng · ml−1 to 7.0 µg · ml−1 (R2=0.9972) with a detection limit (3σ) of 3.0 ng · ml−1. At a flow rate of 3.0 ml · min−1, a complete analytical process could be performed within 0.5 min, including sampling and washing, with a relative standard deviation of less than 3.0%. The proposed method was applied successfully in the assay of puerarin in pharmaceutical injection and human urine. The mechanism of chemiluminescence reaction was discussed briefly.