[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-KMnO4 by using DC in sodium hydroxide medium. Using different concentrations of KMnO4, 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 microg x mL(-1). The detection limit (3sigma) is 2.0 x 10(-3) microg x mL(-1). The method has been successfully applied to the determination of DC in a pharmaceutical preparation.