Rapid Determination of Levofloxacin in Levofloxacin Hydrochloride Injections by Coulometric Titration

In 1.0 mol·L-1 of potassium chloride electrolyte solution, the OH- generated by the electrolysis of water at 10.00 mA of constant current was used as coulometric titrant and reacted with the levofloxacin hydrochloride, and the titration endpoint was achieved when the pH of the solution was 7.30. The whole titration process could be completed within 5 minutes, and the content of levofloxacin in the injection was obtained by Faraday's law. The method was used to determine levofloxacin hydrochloride reference solution, giving relative error of 0.16%. The determination results of 4 batches of levofloxacin hydrochloride injections were consistent with the marked values, with RSDs (n=6) less than 0.40% and recovery rates obtained by standard addition method in the range of 99.3%-100%.