A fluorinated chitosan-based QuEChERS method for simultaneous determination of 20 organophosphorus pesticide residues in ginseng by GC-MS/MS.

Abstract

In this study, a new fluorinated methacrylamide chitosan (MACF) was synthesized and evaluated as adsorbent in the dispersive solid-phase extraction (d-SPE) for the effective determination and extraction of 20 organophosphorus pesticides from ginseng samples by the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method couple with gas chromatography-tandem mass spectrometry (GC-MS/MS). The properties of MACF were characterized by Fourier transform infrared spectroscopy, elemental analysis and high resolution 19 F NMR. MACF, chitosan, primary and secondary amine, octadecylsilane, graphitized carbon black, Z-Sep, Z-Sep+ , EMR-Lipid were compared in terms of extraction efficiency. The best results were obtained when MACF was used. Matrix-matched calibration was employed for quantification. All the organophosphorus pesticides exhibited good linearity (r2 >0.9969) with the concentration at their respective concentration ranges. The limits of detection (LOD) were 1.5-3.0 μg/kg, and the limits of quantification (LOQ) were 5.0-10.0 μg/kg. The trueness of the 20 pesticides at four spiked levels were ranged from 86.1-111.1 % with the RSD were less than 11.3 %. The modified QuEChERS method using MACF as the adsorbent was sensitive, reliable, cost-effective, and could be used for the determination of 20 organophosphorus pesticide residues in ginseng.