Structure identification and quantitative analysis of related substances in cefixime preparations
Objective To establish a method for structural identification and quantitative analysis of related substances in cefixime preparations.Methods The main impurities were identified by HPLC-Q-TOF-MS/MS.Related substances in cefixime were separated on an C18 column(250 mm ×4.6 mm,5 μm)with the mobile phase of acetonitrile-tetrabuthylammonium hydroxide solution and detected at 254 nm.Column temperature was set at 40 ℃.Results Nine impurities in the preparations of cefixime were identified as impurity A,B,D,E,F,G,H,cefixime sulfoxide and cefixime tert-butyl ester.The method could achieve baseline separation.Impurities E,G and H were linear within the range of 0.193 4-20.03 μg·mL-1,r>0.999 0,and the recoveries were 98.4%-101.8%(RSD<2.0%).Conclusion HPLC-Q-TOF-MS/MS technology can preliminarily identify the impurity structure of cefixime preparations.The method can accurately detect the related substances in 26 cefixime preparations with a good specificity and high sensitivity.
high performance liquid chromatographycefixime preparationrelated substancetime of flight mass spectrometry