Study On Enantiomer Separation Of Triazole Chiral Fungicides With Supercritical Fluid Chromatography

Many enantiomers of chiral agricultural pesticides show different biological activities and toxicity, so the separation of enantiomers is very important. In this paper, the enantioseparation of several typical chiral pesticides(herbicide ) were investigated on two commercial polysaccharide -derivative chiral column using supercritical fluid chromatography (SFC) and high performance liquid chromatography (HPLC).At first, the chiral separation of seven triazole fungicides was performed on Chiralcel OD and Chiralpak IB using SFC and HPLC. The influence of chiral stational phase, temperature, mobile phase additives and its concentration on the enantioseparation was studied. At last, five fungici des such as triadimefon, hexaconazole, uniconazole, myclobutanil, and difenoconazole got baseline separation on Chiralpak IB. On Chiralcel OJ, only tebuconazole and imaizole got baseline separation. Using SFC, the highest Rs values of myclobutanil, triadimefon, hexaconazole, tebuconazol e, uniconazole and difenoconazole on Chiralpak IB were 15.47, 1.28, 5.25, 1.85, 2.28 and 1.06/0.735 respectively, the highest Rs values of myclobutanil, hexaconazole, imaizole, tebuconazole and uniconazole on Chiralcel OJ were 1.02, 0.86, 3.98, 5.8 and 1.42 respectively. Using HPLC, the highest Rs values of myclobutanil and imaizole on Chiralpak IB were 9.11 and 0.75, on Chiralcel OJ were 2.12 and 3.52.Secondly, ethofumesate, diclofop-methyl, acetofenate, and benalaxyl were separated on Chiralpak IB and Chiralcel OJ using SFC and HPLC. The influence of chiral stational phase, temperature, pressure, mobile phase additives and its concentration on the enantioseparation was studied. At last, all the four pesticide were baseline separated. Using SFC, the highest Rs values of acetofenate, benalaxy, ethofumesate and diclofop- methyl on Chiralpak IB were 1.47, 4.68, 3.03 and 4.41 respectively, the highest Rs values of benalaxy and diclofop-methyl on Chiralcel OJ was 3.18 and 1.18. Using HPLC, the highest Rs values of benalaxyl and diclofop-m ethyl on Chiralpak IB were 5.44 and 4.81, on Chiralcel OJ were 1.79 and 1.36.