Jian Wang, Dan Ruan, Wei-guang Shan
May 1, 2013
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0
Influential Citations
5
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Journal
Journal of Liquid Chromatography & Related Technologies
Abstract
The twelve impurities and isomers in cefmenoxime hydrochloride were separated and identified by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MSn). A discipline of mass fragmentation pattern and structure for the E-isomer and Δ3-isomer of oxime cephalosporin antibiotics was presented to distinguish their structures. The column was Alltima C18(250 × 4.6 mm, 5 µm). The mobile phase was water-acetic acid-acetonitrile (85:1:15). In positive mode, full scan LC-MS was first performed in order to obtain the m/z value of the protonated molecules of all detected peaks. LC-MS-MS and LC-MS-MS-MS were then carried out on the compounds of interest. The complete fragmentation patterns of twelve impurities were studied and used to obtain information about the structure of these impurities. The relationship of mass fragmentation pattern and structure for cefmenoxime, E-isomer of cefmenoxime and Δ3-isomer of cefmenoxime was studied. The structures of the twelve impurities and isomers in cefmenoxime hydrochloride were deduced based on the HPLC-MSn data, assisted by the UV spectra and stress testing.