Study On The Enantiomerseparation By HPLC And Thermodynamics Mechanism Of Chiral Pesticide

There are big differences of activities, metabolization and toxicity for the enantiomers of a chiral pesticide in the environment because of the different stereochemistries. Also their endurances and effects of biochemical process in the environment are different. Therefore, rapid and sensitive methods for the resolution and quantification of the individual optically pure enantiomers are of great importance. Chromatographic methods have become of considerable interest in recent years, especially in the past 20 years. But many chiral recognition mechanisms for enantiomers are not clear and in our country the relative research is underway. In this paper, some pesticide enantiomers were separated, such as quizalofop-ethyl, napropamide, dichlofop-methyl, metolachlor and metalaxyl by AD-RH and OD-RH chiral columns. The enantiomseparation and thermodynamics mechanism of the chiral pesticides were Studied.The experiment results showed that the resolution of quizalofop-ethyl was good while using AD-RH column, but it can't be separated on OD-RH column. Dichlorop- methyl can not be separated by AD-RH column, but there was good resolution with OD-RH column. Napropamide, metolachlor and metalaxyl can be separated well by both AD-RH column and OD-RH column. Generally speaking, the resolutions of the above chiral pesticide were more than 1.5.In this paper, the separation mechanism of quizalofop-ethyl on AD-RH column, napropamide and metalaxyl on AD-RH column and OD-RH column were researched with thermodynamics. For comparing the difference of separation chiral pesticides on AD-RH column and OD-RH column CSPS the thermodynamics means were used, which will be useful to value chiral column and to research thermodynamics mechanism.