Identification of the main impurities of cefathiamidine by LC-MS

Objective To identify the structure of impurities beyond the reports limits(0.05%),cefathiamidine products of our company and three domestic companies were detected.Methods The forced degradation experiments,long term retention samples and spectroscopy for impurities in cefathiamidine were respectively investigated by HPLC,LC-MS and NMR.Results Four impurities were detected exceeding the report limits,in which deacetylation of cefathiamidine and cefathiamidine lactone were degradation products and the other two were 7-bromoacetamide cephalosporanic acid(7-BCA) and Δ2 isomer of cefathiamidine.Conclusion The results were useful to quality control and stability studies for cefathiamidine.