Abstract: Objective: To establish a high performance liquid chromatography method for the detection of related substances in norfloxacin glucose injection. Methods: Chromatographic column is SHISEIDO C18 column（4.6 mm × 250 mm, 5 μm）, mobile phase
A is 0. 02 mol/L phosphoric acid solution（adjusted to pH（3.0 ± 0.1）by triethylamine）-acetonitrile（90:10）, and mobile phase B is acetonitrile, with gradient elution in different proportions. Flow rate: 1.0 mL/min; detection wavelength: 278 nm; column temperature:40 ℃; injection volume: 20 μL. The peak area of norfloxacin was used to calculate the content of related substances according to the external standard method. Results: The main component peaks in norfloxacin glucose injection and the peaks of each degradation product can be separated well. Impurity A, E, and H were not detected in 15 batches of samples. The content of impurity K was 0.05%.The average content of single maximum impurity was 0.08%-0.10%, and the average content of total impurities was 0.20%. Research of destructive test under acid, alkaline, oxidation and ultraviolet light, proved that the method has good specificity. Conclusion: The established method has good specificity, high sensitivity, and good separation of each peaks. It can be used for the detection of related substances in norfloxacin glucose injection.

Key words: norfloxacin glucose injection, related substances, high performance liquid chromatography