Identification of the related substances in docetaxel injection by LC-MS/MS

The related substances in docetaxel injection were identified by LC-MS/MS.  Ethyl acetate was used to extract the injection to remove the pharmaceutical excipients.  HPLC separation was carried out on a Hedera ODS-2 column (150 mm × 2.1 mm, 5 μm) with a mobile phase consisting of acetonitrile − 0.1% acetate acid aqueous solution (40∶60).  Electrospray ionization source was set in the positive mode for the LC-ESI-MS/MS, and the ion monitoring modes were full scan and product ion scan.  According to the mass spectra of the related substances, the fragment profiles were explained, and the chemical structures were elucidated.  Docetaxel and its main related substances were well separated.  Nine related substances in docetaxel injection were detected by LC-MS/MS.  Their chemical structures were proposed, and four of them were identified in the docetaxel injection for the first time.  The established LC-MS/MS method is effective in the separation and identification of the related substances in docetaxel injection.  The test results are useful for its quality control.