Simultaneous Determination of Acephate and Isocarbophos in Vegetables by Capillary Electrophoresis Using Ionic Liquid and Sodium Dodecyl Sulfate as Modifiers

In this study, an improved method of capillary electrophoresis for simultaneous detection of acephate and isocarbophos was developed. The ionic liquids (ILs) of 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) and sodium dodecyl sulfate (SDS) were added as modifiers in the background electrolyte (BGE) for capillary electrophoresis to enhance the separation efficiency of acephate and isocarbophos. The separation conditions in terms of the concentrations of the IL, SDS, and pH were optimized. The limits of detection of the method for acephate and isocarbophos were 0.15 and 0.08 mg/kg. The relative standard deviation (RSD) for five replicates of acephate and isocarbophos solution (5.0 mg/L) was 1.9-3.9%, respectively. To evaluate the accuracy of this method, cucumber, cauliflower, spinach, and carrot samples spiked with acephate and isocarbophos were extracted and analyzed with good recoveries from 76.8 to 88.8%. This method was then verified by gas chromatography method.