Rapid identification of the degradation products in cefuroxime aqueous solution by HPLC coupled with unit resolution single quadrupole mass spectrometer and calibrated lineshape isotope profile search(CLIPS)

Objective:To explore a method for identifying the elemental compositions and structures of unknown impurities by using calibrated lineshape isotope profile search(CLIPS) function integrated in MassWorksTM software and HPLC combined with unit resolution single quadrupole mass spectrometer.Methods: Degradation products of cefuroxime aqueous solution were obtained by water bath,further separation was achieved by HPLC-MS,the isotope peak shapes of all ions were obtained by recording the mass spectrometer data in profile form.Both the accurate mass and isotope peak shapes were calibrated by CLIPS,which enabled elemental composition determination of the unknown degradation products by using one known ion as the internal calibration.Results: Seven degradation products were separated completely.The elemental compositions of all the quasi-molecular ions and partial fragment ions were rapidly and successfully determined by CLIPS,and the structures of four degradation products were preliminarily confirmed according to their fragmentation behavior in positive mode.Conclusions:CLIPS can help determine the elemental composition of degradation products in pharmaceutical products even using a unit resolution single quadrupole mass spectrometer,and further benefit to simplify the structure elucidation and confirmation.