It elaborates the definitions of epimer and epimerization, states the applications of epimerization in medicine and pesticide,and points out its expansive prospect .

阐述了差向异构和差向异构化的定义。差向异构化技术在医药和农药中间中应用广,前景广阔。

RESULTS The chlortetracycline's epimer, tetracycline and its epimer, as impurities in chlortetracycline have been determined by the liquid chromatogram and its first order mass spectrum.

结果得到金霉素样品液相色谱图以及液相色谱峰对应的一级质谱图。对谱图进行分析,测金霉素样品中含有四环素、差向异构四环素和差向异构金霉素杂质组分。