title: [Determination of unknown impurities in cefotiam hexetil by HPLC-MS/MS].
abstract: OBJECTIVE
  To detect unknown impurities in raw drug material of cefotiam hexetil.
  
  
  METHODS
  High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed for the determination of impurities in cefotiam hexetil. Agilent SB-C18 column (150 mm x 2.1 mm i. d. , 3.5 microm particles) was used for chromatographic separations of cofotiam hexetil dissolved in deionized water, with mobile phase consisting of (A) 0.1% formic acid and (B) acetonitrile and timed gradient program T (min)/B (%): 0/3, 5/3, 15/20, 20/40, 30/60, 40/80. The flow rate was set at 0. 3 mL/min with DAD detector wavelength fixed at 254 nm. Electrospray ionization source was applied and operated in positive ion MRM mode. The source voltage was kept at 4 kV and cone voltage was 100 V with the mass range m/z 50-1000. Nitrogen was used as nebulizing gas and the nebulizer pressure was 40 psi. The drying gas temperature was 350 degrees C and the drying gas flow was 10 L/min. Results Unknown impurities of cefotiam hexetil were identified. Substance 1 was delta3-isomer of cefotiam hexetil. The structures of 3 other substances were also determined.
  
  
  CONCLUSIONS
  The method is sensitive, rapid and credible for the analysis of cefotiam hexetil and its related impurities, which can be applied in quality control of cefotiam hexetil.
authors.affiliation: Department of Forensic Toxicological Analysis, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041, China.
authors.forename: Qun-Xing
authors.initials: QX
authors.lastname: Tang
authors.forename: Ming-Dong
authors.initials: MD
authors.lastname: Liu
authors.forename: You-Yi
authors.initials: YY
authors.lastname: Yan
authors.forename: Yi
authors.initials: Y
authors.lastname: Ye
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Wang
authors.forename: Lan-Fen
authors.initials: LF
authors.lastname: Zhan
authors.forename: Lin-Chuan
authors.initials: LC
authors.lastname: Liao
mesh_terms: D015310:Cefotiam / Q000031:analogs & derivatives* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination / Q000517:prevention & control; D011786:Quality Control; D053719:Tandem Mass Spectrometry
chemical_list: D015310:Cefotiam; C067049:cefotiam hexetil