Determination of sodium chloride in the ofloxacin and sodium chloride injection by catalytic spectrophotometry

Objective:A new simple and sensitive catalytic spectrophotometry method for the determination of sodi- um chloride in the ofloxacin and sodium chloride injection was established.Method:The absorption of methyl red at the wavelength of 519nm decreased due to the decoloration of methyl red in a oxidation reaction with potassium bro- mate being catalyzed by sodium chloride in a medium of dilute sulfuric acid solution.The amount of sodium chloride could be determined based on the quantity relation between decrease of absorption and the amount of sodium chlo- ride.Results:The decrease of absorption was linearly proportional to sodium chloride concentration in the range of 0 -22 μg·mL~(-1).Detection limit of the method was 1.23×10-6 μg·mL~(-1) and the recovery was 96.4% - 98.7%.Conclusion:The method is simple,quick and precise and its assay result is suitable for the quality control of sodium chloride in the ofloxacin and sodium chloride injection.