目的 建立头孢噻吩杂质A的首批国家标准物质,为2020年版《中国药典》头孢噻吩的检测提供必需的标准物质。方法 首先,采用红外、质谱和核磁共振的方法对头孢噻吩杂质A进行结构确证。其次,采用2020年版《中国药典》头孢噻吩有关物质检查项下的方法,测定头孢噻吩杂质A的纯度。然后,测定头孢噻吩杂质A的干燥失重和炽灼残渣。最后,采用质量平衡法对首批头孢噻吩杂质A国家标准物质进行赋值,同时采用核磁定量法测定其含量,与质量平衡法测得的结果相互验证。结果 头孢噻吩杂质A与2020年版《中国药典》规定的结构相同,质量平衡法测定头孢噻吩杂质A的含量为97.8%,与核磁定量法测定的结果基本一致。结论 建立了首批头孢噻吩杂质A的国家标准物质。

OBJECTIVE To establish the first batch of national reference material for cefalotin impurity A, and provide necessary reference material for implementation of the detection method of cefalotin in Chinese Pharmacopoeia 2020. METHODS First, the structure of impurity A was confirmed by IR, MS and NMR. Then, the purity of impurity A was determined by the method under the related substances inspection item of Chinese Pharmacopoeia 2020. The drying weight loss and ignition residue of impurity A were also determined. The mass balance method was used to determine the national standard of the first batch of impurity A. Finally, a nuclear magnetic quantitative method was used to determine its content, which was verified with the results of mass balance method. RESULTS The content of impurity A in cefalotin determined by mass balance method was 97.8%, which was basically consistent with the result of NMR quantitative analysis. CONCLUSION The first batch of national reference material for cefalotin impurity A is established.