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

阐述了差向异构体和差向异构义。差向异构技术在医药和农药中体中应用广泛,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.

结果得到金品液相色谱图以及液相色谱峰对应一级质谱图。对谱图进行分析归纳,推测金品中含有四环、差向异构四环和差向异构金杂质组分。