A Modified QuEChERS Method for the Extraction of Imidacloprid Insecticide from Date Fruit

Abstract

In this study, QuEChERS as a sample preparation method followed by high-performance liquid chromatography was applied to the determination of imidacloprid insecticide in date fruit. According to the comparison of obtained results, the original QuEChERS method was more effective for clean-up than the modified buffered QuEChERS versions. To improve the clean-up efficiency of the date matrix and extraction recovery of imidacloprid, effective parameters of the dispersive solid phase extraction step of QuEChERS including sorbent type and amount were optimized. The obtained results showed that using single-walled carbon nanotubes led to a much cleaner chromatogram without a significant decrease in the extraction recovery of imidacloprid. Under optimum conditions, the concentration range of the calibration curve was 36-900 µg L-1 with a coefficient of determination of 0.9985 and a limit of detection of 11 µg L-1. The intra- and inter-day accuracy and precision of the proposed method yielded relative recoveries of 93-102% and a relative standard deviation of less than 5%, respectively.

Keywords

• matrix effect
• modified quechers
• pesticide residue analysis
• sample preparation
• single-walled carbon nanotube