Separation and Determination of Chiral Difenoconazole in Dragon Fruit by Solid phase Extraction Coupled with High Performance Liquid Chromatography

KeyWord:solid phase extraction(SPE)  high performance liquid chromatography£¨HPLC£©  dragon fruit  difenoconazole enantiomers  chiral pesticides

Abstract:

      A method was established for the determination of chiral difenoconazole in dragon fruit by solid phase extraction coupled with high performance liquid chromatography.The dragon fruit samples were extracted with acetonitrile£¬and purified with carbon black/amino solid phase extraction column.Effects of different chiral columns£¬mobile phase compositions£¬flow rates and injection volumes on chiral separation were investigated.The optimized chromatographic conditions were as follows£ºthe chromatographic column£ºIF-3 chiral column£¬mobile phase£ºn hexane-ethanol£¨92¡Ã8 by volume£©£¬injection volume£º60 ¦ÌL£¬flow rate£º1ª±0 mL/min.Under the optimized conditions£¬the four difenoconazole enantiomers were basically achieved baseline separation£¬and the analysis time was less than 35 min.There existed a good linearity for each enantiomer in the range of 0ª±10-10 mg/L£¬with a detection limit of 0ª±025 mg/L.The average recoveries for the chiral difenoconazole in dragon fruit at two spiked levels of 0ª±4 mg/kg and 2ª±8 mg/kg were in the ranges of 83ª±7%-99ª±3% and 86ª±4%-91ª±6%£¬with their RSDs of 1ª±3%-7ª±2% and 1ª±4%-3ª±1%£¬respectively.The developed method is rapid£¬accurate and sensitive£¬and is applicable for the determination of chiral difenoconazole residues in dragon fruit£¬etc.