Rapid Enantioseparation and Determination of Isocarbophos Enantiomers in Orange Pulp, Peel, and Kumquat by Chiral HPLC-MS/MS

Abstract

The enantioseparation and determination of isocarbophos enantiomers in orange pulp, peel, and kumquat by chiral HPLC tandem mass spectrometry (HPLC-MS/MS) are presented. Four cellulose-based chiral columns and two amylose-based columns were employed to explore the influence of chiral stationary phase on the enantioseparation selectivity and elution order of isocarbophos enantiomers. The fastest baseline enantioseparation of isocarbophos was achieved on amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD-3R) with acetonitrile and water (containing 2 mmol L−1 ammonium formate and 0.1 % formic acid) (60:40, v/v) as mobile phase. The influence of temperature on enantioseparation of isocarbophos was investigated, indicating that the enantioseparation of isocarbophos on Chiralpak AD-3R columns was an enthalpy-driven separation. The method performance including linearity, sensitivity, matrix effect, and precision was evaluated. Under the optimized conditions, the recoveries of the isocarbophos enantiomers in orange pulp, peel, and kumquat were 76.1–95.4 % with RSD lower than 11.1 % at 5, 50, and 250 μg kg−1 levels. The limits of detection ranged from 0.2 to 0.5 μg kg−1 for enantiomers in orange pulp, peel, and kumquat. Application of the proposed method to the real sample analysis suggested its potential use in the enantioselective determination of isocarbophos in food samples.