Flow injection analysis of trace amounts of doxycycline with inhibited chemiluminescence detection

A novel flow injection chemiluminescence method has been developed for the determination of doxycycline(DC) based on the inhibition of chemiluminescence reaction of Luminol-KMnO 4 by using DC in sodium hydroxide medium. Using different concentrations of KMnO 4, a series of good linear regression equations of decreased chemiluminescence intensity and the concentration of DC were obtained with different subsections in the concentration range of 0.005-5.0 μg·mL -1. The detection limit (3σ) is 2.0×10 -3μg·mL -1. The method has been successfully applied to the determination of DC in a pharmaceutical preparation.