Chiral Resolution Applied Research Of Four Racemic Pesticides On Chiralpak As-h Chiral Column By High Performance Liquid Chromatography

Chirality is one of the essential attributes of nature. The physical properties of melting point, boiling point, relative density, refractive index, the solubility in solvent and spectra of chiral enantiomers are the same, but due to the different effects of physical properties for the polarized light, they are of opposite directions with the same rotation capacity. Although the physical and chemical properties of enantiomers are almost identical, biochemical and pharmacological effects are often different. Generally speaking, Chiral neutral and physiological activity compounds is often effective but its enantiomer merely invalid. Chiral pesticides with marked specificity of three-dimensional have nearly identical physical and chemical characteristics, but its bioactivity, toxicity, metabolism, residues are of great differences. However, most chiral pesticides are producted and emploied in the form of raceme,the invalid or inefficient isomers not only reduces the pesticide effect, but also brought the environmental pollution and so on. Therefore, establishing effective separating and analysising methods of chiral palys a significant role on the detection of chiral pesticides quality, conducting the using of pesticides, saving the relevant materials, avoiding pollution of the environment.High performance liquid chromatography (HPLC) method was proved to be the most convenient, reusable and widely used method in all the chiral separation technologies, and one of the easiest and most effective methods is chiral stationary phase HPLC (CSP-HPLC). At present, more than 100 HPLC have been commercialized. Therefore, the study on chiral resolution in pesticide effect is of extensive significance.The Daicel CHIRALPAK AS - H column for the chiral stationary phase, under high performance liquid chromatographic separation conditions, several chiral pesticides (Triadimenol,Tebuconazole,Diniconazole,Lambda-cyhalothrin) could be analysised and preparated and be directly splited. CHIRALPAK AS - H directly splited chiral pesticides of Triazole and Pyrethroids for the first time.This paper designed a screening methods of separating condition. Firstly, according to the high performance liquid chromatography (HPLC) mobile phase modifier varieties and contents, secondly, according to preliminary experimental results obtained the content of best spliting conditions under the modifier environment. The results showed that under the conditions of room temperature and velocity of 0. 5 ml/min, the optimal condition of CHIRALPAK AS - H column studying separation show that: normal hexane/ alcohol= 95/5 for triadimenol, separating degree is 2.00; normal hexane/isopropanol = 90/10 for Tebuconazole , separating degree is1.41; normal hexane/isopropanol = 90/10 for Diniconazole, separating degree is 2.76; normal hexane/isopropanol = 90/10 for Lambda-cyhalothrin, separating degree is 1.81.