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

阐述了差向异体和差向异定义。差向异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.

结果得到金霉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,推测金霉中含有四环、差向异四环和差向异金霉杂质组分。