Stereoselective quantitation of haloxyfop in environment samples and enantioselective degradation in soils

The chiral separation of haloxyfop enantiomers was first performed on (R, R) Whelk-O1 chiral column (pirkle type) by high-performance liquid chromatography (HPLC). Chromatographic conditions such as mobile phase composition and column temperature were optimized, and the best resolution was obtained using hexane/n-propanol (98/2) with Rs value of 3.43. Chiral residue analysis methods for haloxyfop enantiomers in environmental matrices, such as soil and water, were developed with recoveries ranging from 85.95% to 104.25%. The results showed that these methods were effective enough for detecting the residual enantiomers environmental matrices. The behavior of haloxyfop in four soils was studied and the enantioselective degradation was found with enantiomer fraction values ranging from 0.058 to 0.61. The research work was extremely useful for investigating the fate of individual enantiomers in environment, the mechanism of the stereoselective behaviors, and the risk assessment of chiral pesticide.