Evaluation of an alternative fluorinated chitosan as a QuEChERS adsorbent for pesticide residue analysis in apple samples

Abstract

In this study, a new and green fluorinated chitosan (trifluoroethyl methacrylate-chitosan (TFEMA-CTS)) was synthesized, and the QuEChERS method was applied for the effective determination of four pesticide residues in apple samples by high performance liquid chromatography. The properties of TFEMA-CTS were characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, elemental analysis and thermogravimetric analysis. The performance of TFEMA-CTS as an adsorbent was compared with that of primary secondary amine, octadecyl silica, chitosan and ethyl methacrylate-chitosan, and TFEMA-CTS had the best effect on clean-up efficiency while ensuring good recoveries of analytes. The amount of adsorbents that affected the clean-up efficiency of QuEChERS was optimized. The limit of detection (LOD) of the method for four pesticide residues ranged from 1.90 to 6.80 μg kg⁻¹ and the limit of quantification (LOQ) of the method ranged from 6.10 to 22.0 μg kg⁻¹. Good linearity (R ≥ 0.9854) was achieved at concentration levels of 0.1–200.0 mg kg⁻¹, and acceptable method precision was found as intra- and inter-day precisions, yielding relative standard deviations less than 4.8%, respectively. TFEMA-CTS as a potential adsorbent showed strong ability of removing the matrix, and it achieved great ability to retain the targets. It will provide a new choice for detecting pesticide residues in apples, and it is possible that the method may also be extended to other types of samples and analytes.